DIVE LOG AUSTRALASIA FEB 2025 ISSUE 410

FEBRUARY 2025 | No 410 digital

AUSTRALASIA

FEATURING the GREAT BARRIER REEF

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Swallow tail sea slugs DAVID MULLINS ASHMORE REEF CATHIE & TERRY CUMMINS

RAINE ISLAND MIKE SCOTLAND

Swimming with Sharks MIKE SCOTLAND

EQUATOR DIVING KEN HOPPEN

Wakatobi a beacon for the future MIKE SCOTLAND

MVOCEANIA/J' Our newest dive liveaboard operating out of Walindi Resort since 2019. Diving Bismarck Sea and Milne Bay

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mv

LIVEABOARD MV FeBrina has been operating from Walindi Resort since 1991. Bismarck Sea, Including New Britain & Kavieng

Walindi Plantation Resort celebrates 40 years of operation. Diving Kimbe Bay Reefs

Scubapro.com/SeizeYourMoment

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Dive Log always celebrates the miracle of life and the beauty in the oceans. The greatest experience in life is adventure, discovery and communication with Mother Nature. Plonk on a face mask, dip into the water and observe as the adventure begins. The oceans have so much living abundance. Every single lifeform you focus on can illustrate this point. Take Garden Eels. I saw patches in Fiji. over my many hundreds of dives. I am a numbers man so I do a rough population count. One garden Eel. Two Garden Eels… just like Count von Count from Sesame Street. Continuing on, I estimate the population in one square metre in one patch; then the total area and finally approximate the numbers of patches… then do the sums. Warning here, we are in the challenge of elementary arithmetic. I come up with hundreds of millions of Garden eels around the rich waters of Fiji. Next, I observe these beautiful little critters reaching up into the current to gobble down plankton; shrimps, larvae, eggs and more. I guess they will eat hundreds of them each day. The total food source is now numbered in the many billions. Each year, trillions get eaten. Next level includes the entire food web including all fish and sea life. We are talking Googles of life forms. Ten to the power of a hundred. (one with a hundred zeros) You get the picture. The Mother Nature is mind blowing. The super abundance is there. It is spectacularly mind blowing and you have used some basic garden logic to see the incredulity of the Ocean. It is a place of real magic. A place to be revered, admired and celebrated; a place to be preserved. That is why I like to say. The greatest experience on earth is discovery and then to polish it with thought. Our ocean is a brilliant place to encounter the greatest adventures of all. Everywhere you go it is jam packed with life. I met a Marine Biologist who studied viruses and tiny organisms in water. He said millions of viruses and life molecules live in every drop. This why I always tell my Marine Biology students that none of us has seen more than 1% of marine life that is under our noses, even after forty-eight years of active diving, in my case. You could go on. Tiger shark eat thousands of fish to get to four metres. Whales have eaten countless numbers and so on. This brings us to the concept of NET ZERO. The greatest tragedy in the ocean is illustrated by this anecdote. Fishermen from Botany Bay used to net the beach at Kurnell in the 1960’s and haul in tonnes of fish. Salmon Haul Bay at Cronulla was renowned for netting tonnes of salmon. Lilli Pilli had massive schools of Luderick and Grey Nurse Sharks. Nowadays, all gone! Fifty years ago, Tuna Fishermen scooped up eighty tonnes of Tuna in one net down off the Sth coast of NSW. OUR COVER PHOTO OUR FRONT COVER photo by Mike Scotland is a friendly female Leopard shark taken at Wooli, Nth Solitary Island. Leapard sharks migrate south from the Great Barrier Reef in summer.

A year or two later, the Net haul was less than one tonne. Tuna fishing has become uneconomic and unviable. They never returned a few fish to be the breeding stock for the future. Therefore, net zero! Today, the seas around Sydney are empty. It is a place of desolation where fish life sits at about two per cent of its capacity. This is an absolute shame! The tragedy is that most people dive in and think that it is ‘normal’. The empty sea is a direct result of overfishing and pollution. Divers see examples of the wrong type of human activity all too often. A discarded two-metre wide Smooth sting ray carcass with its wings chopped off. Blue gropers and Red Morwong with non-fatal wounds from spear guns. High Nitrogen pollution from septic systems. The hullaballoo about Net Zero in parliament ignores my reality of diving in Sydney. The zero fish life in the nets. The empty ecosystems out of balance and devoid of life. An Australian Scientist calculated that the photosynthetic activity of Australia absorbs between five and ten times all of the Carbon resulting from all human activity. Australia is already Carbon positive, ten times over! Net Zero for marine life is a far more important issue in my mind. Empty nets, barren seas, desolate oceans, overfishing, pollution and all other forms of man-made disasters mean that every ecosystem in the ocean is so far out of balance that it is a crime. Humankind has been mindlessly operating on an unlimited ‘take, take, take’ policy and giving almost nothing back. Overfishing is nothing short of marine vandalism. The ocean will provide enough food for the planet if managed properly. So few of us are aware of this issue. So the question arises. What can we do about it? Education is the answer. Tell the world! Tell a hundred people. Let the public know that we can and will save the Great Barrier Reef. All we have to do is to monetize it. Each acre has a dollar value either as a fish breeding area, a tourist attraction or research area. The sea is treated as worthless in terms of real estate, place to be exploited and dump rubbish. The reality is that humans desperately want to commune with wild life and see amazing things. We are hard wired to Nature! I predict a significant rise in the popularity of nature based recreation in the future. As more people are forced by economics to live in units, they will crave contact with nature. The oceans and mountains will become even more popular as people need to see the fish corals and forests up close and personal. I hope that the scuba diving industry in Australia will grow back to the halcyon days of the eighties once again. That is part of the mission of Dive Log Australasia. This issue has many inspiring articles on Sea Slugs, great dives, swimming with sharks and much more. Read on, share with other divers and enjoy.

Mike

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A pair of Long Nose Hawkfish perched on a Gorgonian Sea Fan.

Photo Hints: The key to providing a Blue Background required the use of the normal Macro image exposure of F16 – F22 but the use of a very slow shutter speed setting of ¼ Second Although such shutter speeds can result in a blurred image, the extreme short duration of strobe illumination will assist in preventing blur and a very steady cameraman will help to prevent camera movement blur at such a slow shutter speed. Interesting Facts: Hawkfish are effective predators of small baitfish and rely on their ability to perch and launch a sudden attack on their prey. They commonly return to the same coral perch time after time. Such predicable behav iour can be very beneficial to the patient photographer.

Most images of Macro subjects feature a black back ground. This is due to exposures of F16, F22 or even higher and shutter speeds of 1/125 to 1/250 of a second which works well for exposing the key subject with strobe light but such settings will rarely capture sunlight illumina tion that could provide a nice blue background should this be desirable. This Hawkfish provided a great opportunity to shoot a macro image with the beautiful blue ocean background also captured and therefore revealed. Image: by Kevin Deacon. Location: Bali, Indonesia. Genre: Macro with Strobe & Sunlight Illumination. Photography Data: Nikkor 60 MM macro Lens. ISO 100. F22 @ 1/4 Second exposure.

Scientific Name: Oxycirrhites typus

Kevin Deacon is a pioneer of Underwater Photography. His images have been published World Wide in prestigious books, magazines and advertising media. Kevin and Cherie Deacon operate DIVE 2000 based at Sydney’s, Northern Beaches providing Photo Guided Dive Travel Tours, Photo Guided Africa Wildlife Safaris, Sales of Underwater Photographic Equipment & Training. www.dive2000.com.au

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Dive Log Australasia #410 February 25

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CONTENTS

digital

FERRUARY 2025

N o. 410 NEXT ISSUE DEADLINE : Issue 411 APRIL 2025 Advert bookings 7th Mar Artwork due 15th Mar Editorial material : 7th Mar EDITOR Mike Scotland mike@divelog.net.au Editor/Designer Mike Scotland | divelog@divelog.net.au PUBLISHER mike@divelog.net.au ADVERTISING mike@divelog.net.au MENTOR Barry Andrewartha | barryandrewartha@outlook.com

Features

018 JOHN LIPPMAN RESEARCH ARTICLE 023 RAINE ISLAND - Mike Scotland 032 WAKATOBI - Mike Scotland

037 ASHMORE REEF Dr Terry and Cathie Cummins 042 BLUE KNEED SEA SPIDERS by Lynne Tuck 043 DIVING WITH SHARKS - Mike Scotland 054 SPOTLIGHT Photographs GREAT BARRIER REEF 056 YELLOWSCORPIONFISH -by John Magee 058 SULAWESI WRECKS Fritz Herscheid 064 PFO Cathie Cummins and Dr Cathie Meehan 70 SPIRIT OF FREEDOM by Mike Scotland 077 SILVER TIP SHARKS by - Mike Scotland 099 CITIZEN SCIENCE by Jodi Salmond

Tel: + 61 0415158168 mike@divelog.net.au www.divelog.net.au

Editorial and photographic contribution guidelines: divelog@divelog.net.au

The views expressed by contributors are not necessarily those of the

publishers or its editors. REPRODUCTION OF CONTENTS

No part of the contents of this publication may be reproduced without the prior written consent of the publisher. All images are copyrighted by the authors and photographers.

Regulars

67 - Dive 2000 - Kevin Deacon 68 - In Deep - Simon Pridmore 84 - Equator diving by Ken Hoppen 88 - Sthn Wrecks Steve Reynolds 89 - Sthn Waters Steve Reynolds 90 - Dive Boat Directory 92 - Your Shot

07 - Mike Ball Expeditions

Spoilsport

10 - DAN News 12 - PNG Resort Listings 15 - Diving Medicine Dr Simon Mitchell 20 - NudiNotes - David Mullins 31 - Counter Strike -David Strike 51 - Historical Diving Des Williams 62 - WOW - Dr Yolanda Waters-

95- Parting Shot 96 - ADEX SYDNEY

by Dr Sally Gregory

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DIVE LOG Australasia #410 - February ‘25

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Great Barrier Reef on the January

Mike Ball Dive Expeditions Takes the Lead in Addressing Lithium Battery Fire Risks Lithium battery fires are a growing concern in the marine industry, and Mike Ball Dive Expeditions is committed to pioneering safety solutions. The increasing use of lithium-powered devices, such as underwater cameras, lights, and scooters, while beneficial for divers, presents a significant fire risk. Recognising this challenge, Mike Ball Dive Expeditions has developed a pioneering system for safely charging these batteries on board their vessels. Owner Craig Stephen understands the urgency of this problem. Recent incidents involving devastating fires on vessels in the US and the Red Sea have underscored the importance of proactive safety measures. To address these challenges, the Engineering Department at Mike Ball Dive Expeditions designed and implemented a custom-built charging station that takes a multi-layered approach to safety. Strategically located on the dive deck, the system incorporates advanced features such as fire-retardant and self-extinguishing materials, ventilation to disperse smoke, and a simple design for rapid removal in emergencies. These engineering solutions reflect the department’s unwavering dedication to the safety of passengers, crew, and equipment. Key features of this innovative charging station: • Containment: The box is constructed from fire-retardant and self-extinguishing materials, which are designed to contain a fire and prevent it from spreading. • Ventilation: The open-air environment of the dive deck allows for smoke dispersal, reducing the risk of exposure to toxic fumes. • Easy Removal: The box is designed to be quickly detached and thrown overboard in case of a fire. It is a "simple" design with "no moving parts" like hinges or doors to ensure quick access. • Large Capacity: The box is specifically sized to accommodate the largest scooter batteries, ensuring that all high-risk devices can be charged safely. This size was decided upon after careful consideration of the various batteries used by guests, with the largest scooter battery serving as the benchmark. • Thoughtful Design: The design incorporates considerations for thermal expansion to prevent the box from jamming if it gets hot. • Testing and Refinement: The team is dedicated to the ongoing testing and refinement of the system, which includes conducting fire drills with a float to simulate a real fire scenario and carefully monitoring the electrical circuits for any signs of overload. The dive deck location was chosen for several reasons: • The open space and airflow help to dissipate smoke in case of a fire. • It is close to where the dive scooters and other equipment using large batteries are used. • The location provides immediate access to the water for quick disposal of the box in an emergency. This innovative charging station is just one example of Mike Ball Dive Expeditions' ongoing dedication to passenger and crew safety. By combining practical engineering with a proactive approach to risk management, the company continues to set the standard for responsible diving practices.

PHOTOS FROM NOVEMBER/DECEMBER

1st. Mate Rudas

2nd. Oscar Stachelberg

3rd. Torin Kelderman

Glass out Far North Coral Sea Exploratory at Green Beret.

Mike Ball’s fire-safe charging station ensures diver safety with fire-retardant materials, ventilation, and quick removal on the dive deck.

Check out availability of Expeditions on Spoilsport. www.mikeball.com/availability

“The reef systems here are some of the most pristine I have seen anywhere in my dive travels around the globe, and Wakatobi resort and liveaboard are second to none. The diversity of species here is brilliant if you love photography.” ~ Simon Bowen

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EVERY DIVER SHOULD BE A DAN MEMBER

For over 40 years DAN has helped divers, like you, in need of emergency medical assistance and has prepared millions of divers for a lifetime of safe diving. That’s why every diver should be a DAN member.

Thomas Bauer Recreational Diver Member since 2003

Marty Snyderman Marine Photojournalist Member since 1988

Kayla Feairheller President & Founder Blue World Member since 2021

Kelly Park PADI IDC Staff Instructor Member since 2013

Paul McQuigg Dive Professional The WAVES Project Member since 2015

Cristina Calderon Signature Dive Veterans Member since 2017

World.DAN.org

SAFETY – MEDICAL – RESEARCH – EDUCATION – DIVE ACCIDENT ASSISTANCE

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DIVE LOG Australasia #410 - February ‘25

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Go Easy on the Ears The diver was a 36-year-old female who had done four dives in the two months since her certification. She was physically fit and in good general health but reported having had intermittent difficulty equalising during her certification dives. The Dives The diver did a series of three dives to a maximum depth of 19.5 metres. She had a minimum surface interval time of an hour between each dive. Her last dive of the day was to 14 metres for 45 minutes. She reported trouble equalising during her first descent and increasing difficulty on subsequent descents. She did not complain of pain or any other significant symptoms, but she did report a feeling of “fullness” in her left ear. She didn’t dive for the next two days, and the sensation of fullness decreased but did not resolve completely. After two days the diver believed she would be able to equalise effectively, and she decided to dive again. Unfortunately, she found equalisation difficult and uncomfortable as she descended. The discomfort persisted to her maximum depth of 17 metres. She continued to dive for about 20 minutes, but when she could no longer tolerate the discomfort, she signalled her buddy, and they initiated their ascent, and the discomfort intensified to the point of pain. This pain, combined with the diver’s inexperience, caused her failure to vent her BCD, and she made an uncontrolled ascent to the surface from 6 metres, during which the pain increased dramatically. She had not completed a safety stop, so she and her buddy attempted to descend to 4.5 metres to perform the missed stop. As they descended, she was unable to equalise, and she made a forceful attempt at approximately 3 metres. She reported feeling and hearing a “pop”, and the pain in her ears became sharp. The diver aborted the descent and managed to return safely to the surface, but she required assistance getting back to shore. Once ashore she was observed staggering and unable to walk without aid. She also became nauseated and vomited several times. She found she couldn’t tolerate lying flat or any movement of her head, both of which provoked nausea and vomiting. The diver’s buddy called an ambulance, and she was transported to the local hospital. The Diagnosis Upon examination, the doctor observed nystagmus (rapid involuntary eye movements) in addition to the acute

nausea and vertigo she reported. Additionally, the diver complained of diminished hearing and a continued sensation of fullness in the left ear. Examination of the ears revealed slight redness of the right tympanic membrane (ear drum) with no other abnormalities. The left lymphatic membrane, however, was markedly red and bulging, and an accumulation of fluid and blood was observed behind the membrane. These signs indicated an injury to the middle ear, but the diver’s symptoms indicated something more serious. The evaluating physician contacted DAN for consultation. Based on the diver’s difficulty equalising, her relatively conservative dive profiles and her forceful equalisation attempt, some type of ear barotrauma was the most likely explanation of her symptoms. The severity of the symptoms seemed to indicate inner-ear barotrauma in addition to that of the middle ear. Inner-ear barotrauma means a perforation of either the round or oval window, the two membranes of the inner ear. This injury is usually treated with bed rest with the head elevated, avoidance of lifting or straining, and medication to relieve the nausea. The purpose of these therapies is to give the perforated membrane a chance to heal, and most individuals recover without complications, as this diver did. Conclusion Remember, if you encounter any equalisation difficulty, stop descending, ascend a metre or two and attempt to equalise again. If you cannot equalise, do not make a forceful attempt; abort the dive instead. Neither middle- nor inner-ear injuries are inherently life threatening, but nausea, vomiting and especially vertigo while submerged can place a diver at great risk. Don’t be complacent when it comes to equalisation, and don’t ignore ear discomfort while diving. Despite expenses paid or plans made, our hearing and lives are much more valuable. World.DAN.org

DIVE LOG Australasia #410 - February ‘25 11

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LOLOATA ISLAND RESORT www.loloataislandresort.com

DIVE KOKOPO & WATER ADVENTURES www.facebook.com/kokopodiveandwateradventures

Luxury Island Resort with 68 - rooms/villas, two restaurants and bar, a swimming pool, recreational beach, fully equipped dive shop, spa and conference centre. Importantly, it sits on the edge of the Papuan Barrier Reef and 29 dive sites around the island where experienced divers can explore its reefs, spectacular sea life and shipwrecks.

Instruction, gear rental, WW2 wrecks, wall dives, reef dives, muck dives, shark dives. Full resort facilities, land & marine tours, wifi, pool. At Kokopo Beach Bungalow Resort with tropical bungalows in the heart of Kokopo-Rabaul with private beachfront. diving@kbb.com.pg

There are also excellent snorkelling sites. Loloata’s PADI-certified dive and activities centre is opened now, so learning to dive is also now an option. t: +675 7108 8000 / 7914 3966 e : gm@loloata.com

NIUGINI DIVE ADVENTURES www.niuginidiveadventures.com

TUFI RESORT www.tufiresort.com

Discover Tufi in a boutique resort with 180 degree panoramic views over the sea and the only fjords in PNG. Experience diving in a secluded paradise with abundant sea life, coral reefs and wrecks. The warm crystal clear waters of Tufi are a divers paradise. Gear rental, water activities, village stays, cultural and land tours. 24 air conditioned ensuite guest rooms, pool, full resort facilities. reservations@tufiresort.com Fly across mainland Papua New Guinea to remote and magical Karawari Lodge. The lodge overlooks the Karawari River whose waters flow towards the Sepik River. Stilted villages line the edges of the waterways. Dugout canoes glide by. Lodge guides introduce guests to the complex and mysterious tribal culture. Conversations with villagers are fascinating. Photo opportunities abound.

The only dive company established within ‘beautiful Madang’; the PADI certified facility, NDA is one of the most experienced dive operators in Papua New Guinea. NDA offers resort courses taught by our team of multi-lingual, PADI certified instructors and dive masters. The crystal clear waters surrounding Madang offer some of the world’s best diving

experiences for divers to discover. Most dive sites are only 5-10mins away! Underwater peaks climbing from 600m to 4m and sheltered lagoons where old wrecks, dating back to World War II, are waiting to be explored... Contact info: nda@madangresort.com

KARAWARI LODGE www.pngtours.com

TAWALI RESORT www.tawali.com

Instruction, gear rental, Nitrox, 22 ensuite rooms, Broadband, full resort facilities.Where it all started, discover the dive sites that place PNG into the world class map of scuba diving. Situated on a limestone bluff backed by densely rain

forested hills overlooking the clear and protected water of Milne Bay, Tawali offers travellers a unique location to dive, relax and enjoy the unspoiled wonders of this magnificent part of the world. reservations@tawali.com

service@pngtours.com

AMBUA LODGE www.pngtours.com

RONDON RIDGE www.pngtours.com

Explore mainland Papua New Guinea based from eco-friendly Ambua Lodge. The lodge is nestled in the highlands, overlooking the magnificent Tari Valley, home of the famous Huli Wigmen. Visit their traditional lands and learn about their fascinating culture. Follow walking trails through mid-montane forest, over traditional vine bridges and along clear mountain streams to secluded waterfalls. Watch for Birds of Paradise.

In the mountains of mainland Papua New Guinea, above the town of Mount Hagen, sits Rondon Ridge. Rising mists enhance the lodge’s panoramic views of the historic valley below. Orchids thrive here. Hours of walking trails offer opportunities to spot exotic birds, including Birds of Paradise. Lodge

guides share the history and traditions of the Melpa people. Rondon Ridge is conveniently accessible on scheduled flights between Port Moresby and Mount Hagen. service@pngtours.com

service@pngtours.com

PACIFIC OCEAN

• Diving is possible all year round with the optimal season typically from mid April to mid June, and mid September to mid December.

KAVIENG

NEW IRELAND

MANUS ISLAND

VANIMO

BISMARCK SEA

• Water temperature from 26º along the edge of the Coral Sea and up to 31ºC in the Bismarck Sea. • Visibility ranges from 50 to 150 ft • PNG has a hyperbaric chamber maintained to international standards • The use of permanent environmental moorings ensures minimal anchor damage to reefs. • Weekly flights to Port Moresby from Singapore, Hong Kong, Tokyo, Manila, Kuala Lumpur, Honiara, Nadi. Daily flights from Cairns, Brisbane, Sydney. • For the best dive and air package pre-book your complete tour with a recognised PNG dive travel specialist.

RABAUL

WEWAK

KIMBE BAY NEW BRITAIN

MADANG

TARI

HOSKINS

MT HAGEN

GOROKA

PAPUA NEW GUINEA

BOUGAINVILLE ISLAND

LAE

SOLOMON SEA

GULF OF PAPUA

TUFI

PORT MORESBY

MILNE BAY

ALOTAU

www.walindiresort.com

www.lissenung.com “Instruction, gear rental, 8 rooms (6 with ensuite, 2 with semi ensuite), free WiFi, full resort facilities. A visit at Lissenung Island Resort is truly exclusive! info@lissenung.com

Instruction, gear rental, Nitrox, 12 bungalows, 8 plantation house rooms, all ensuites, internet, pool, full resort facilities, English. Voted the 'Best diving from a resort anywhere in the world', Walindi comprises fern-draped bungalows set in tropical rainforest gardens on the shores of Kimbe Bay.

resort@walindifebrina.com

MV OCEANIA LIVEABOARD www.mvoceania.com

www.mvfebrina.com

Gear Rental, Nitrox, 10-12 passengers, English MV FeBrina cruises from Walindi Resort, diving Kimbe Bay, Witu Islands, Fathers Reefs, Rabaul and New Hanover. febrina@walindifebrina.com

Gear Rental, Nitrox, 16 passengers, English

MV Oceania is the most recent liveaboard addition to Kimbe Bay. A 27 metre catamaran, Oceania began operation in 2019 with itineraries including Kimbe Bay, Witu Islands and Fathers Reefs as well as further afield at select times of year. reservations@mvoceania.com

Image credit David Doubilet

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W|ä|Çz

numbers of gas micronuclei or other places where bubbles can easily form in blood or tissues. The difficulty in confirming a finding like this in humans is our inability to intentionally subject humans to such dangerously provocative decompressions in experiments. Indeed, although using actual DCS as an outcome measure in human experiments can be justified in some circumstances, the risk of the experimental dives cannot be too high and the studies need huge numbers of subjects if we are seeking meaningful differences in outcome when testing a protective strategy or a different decompression strategy etc. It follows that such trials almost never get done for ethical and economic reasons. It is much more common to use ultrasound counts of the venous bubbles that form after many safe dives as an indicator of “decompression stress”. This involves a presumption that reducing these bubble counts indicates a safer dive. Pre-dive exercise has undergone this type of testing in humans, and the results are confluent with the animal studies. Intense exercise at any time between 24 hours and immediately prior to diving has been shown to reduce the formation of bubbles in the venous blood of human subjects after diving. There are 5 or 6 papers that have looked at this and there were no contrary results (although one did show benefit of exercise at 2 hours but not 24 hours prior to diving). This level of confluence strongly suggests that the effect is real and something that we should take notice of. It does seem likely that exercise prior to diving will reduce the risk of DCS. Translating that finding into real-world practice is challenging and given the risk of DCS is very low in typical recreational scuba air diving, it is not necessary to aggressively advocate the “exercise before diving” strategy. However, it is an option for risk reduction that technical divers performing more risky dives might bear in mind. “Intense exercise” means something like a 30 – 45 minute run or cycle ride as fast as you are comfortable going, and this level of EXERCISE AND DIVING: DOES IT AFFECT RISK OF DECOMPRESSION SICKNESS Professor Simon Mitchell, University of Auckland.

`xw|v|Çx I wrote in my last article that one of the subjects of consistent interest to divers is the issue of how to minimise their risk of suffering decompression sickness (DCS). I pointed out that everybody appreciates that the depth-time profile of a dive is of paramount importance in determining this risk. But what divers are frequently referring to when they ask questions about risk minimisation are those factors other than depth-time profile that may be relevant. In the last article I discussed the potential effect of water temperature on risk, but pointed out that there are other important factors such as exercise. It is exercise that I will discuss in this article. The relationship between exercise and risk of DCS is one of the most complex issues in the pathophysiology of this fascinating disorder. It turns out that exercise can be your friend or enemy, depending on when you perform it, and to some extent on its intensity. Specifically, exercise can have very different implications depending on whether it occurs before a dive, during bottom time, during decompression, or after the dive. For my money, one of the most intriguing discoveries in diving medicine in the span of my career has been the finding that pre-dive exercise may reduce the risk of DCS, perhaps dramatically so. This started in the early 2000s with an experiment by a Norwegian group which aimed to determine whether being fit reduced the risk of DCS. The work was performed using a rat model of DCS (yes, you can train rats to be fit – or not). To cut a long story short, they showed that even a single bout of exercise about 20 hours before a decompression that resulted in death of most rats seemed to prevent serious (and sometimes any) manifestations of DCS. It did not seem to relate to being fit so much as the timing as the last bout of exercise prior to diving, and even a single properly timed exercise session was protective. There has been much discussion of the possible mechanism, and this is beyond the scope of this article. It probably has something to do with transiently reducing 15 Dive Log Australasia #410 February 25

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activity is not within everyone’s level of capability. Moreover, care needs to be taken not to become dehydrated if the exercise is conducted very proximal to diving. Finally, because exercise after diving is not a good idea (see below) it is a difficult strategy to implement in multi-day diving over sequential days. Exercise at other stages of dives has mixed implications. Heavy exercise during bottom time is a definite disadvantage because exercise increases blood flow through tissues and thereby enhances the uptake of inert gas breathed at higher pressures during the bottom phase of the dive. A sensible perspective should be maintained on this issue. Obviously, some exercise is required to swim around and enjoy a dive, but what should be avoided, if possible, is prolonged heavy exercise at depth. Diver propulsion vehicles (DPVs) or “scooters” are a great help in this regard, and the group arguably most likely from their use is technical divers performing decompression dives. Exercise during decompression is potentially beneficial for the same reason. That is, continued mild exercise whilst decompressing enhance blood flow through tissues and thereby helps carry inert gas which is now leaving tissues back to the lungs. Rather than simply hanging at a safety stop or decompression stop, divers could usefully maintain gentle finning which will help outgassing. Note however, that more is not necessarily better in this setting because heavy exercise can promote the transfer of venous bubbles into the arterial circulation (see below). Exercise after a dive, particularly deep or decompression dives, is generally discouraged. There is a period (lasting hours) after surfacing when tiny bubbles often form in the veins. They are carried back to the lungs where they get trapped in the lung capillaries and the gas inside them is absorbed. In the vast majority of situations these bubbles are harmless. However, if a diver indulges in exercise while these bubbles are arriving in the lung circulation then there is a greater chance of them failing to be filtered out by the lungs. If these bubbles pass through the lungs into the arterial circulation, there is more potential for them cause harm. In addition, if the diver has a patent foramen ovale communication between the two upper heart chambers, exercise may make it more likely that the bubbles will cross the PFO from the veins into the arterial circulation. Divers should generally avoid significant exercise, including heavy lifting and straining for at least 4 hours after diving. In summary, if we want a simple characterization of the relationship between exercise and diving, it might

go like this: before = good, bottom = bad, decompression = good, surface = bad. No need to be obsessive about it, but there are options for risk reduction for those interested in taking them.

Professor Simon Mitchell MB ChB, PhD, DipOccMed, DipAdvDHM (ANZCA), FUHM, FANZA Simon works as an anaesthesiologist at Auckland City Hospital and is a Professor of Anaesthesiology at the University of Auckland. He provides on-call cover for the diving emergency service in New Zealand. He is widely published with two books and over 160 scientific journal papers or book chapters. He co authored the hyperbaric and diving medicine chapter for the last four evrsions of Harrison’s principles of Internal Medicine. He has been Editor-in-Chief of Diving and Hyperbaric Medicine Journal since 2019. He has twice been Vice President of the UHMS and in 2010 received the society’s Behnke Award for contributions to the science of diving. Simon has a long career in sport, scientific, commercial, and military diving. He was first to dive and identify three historically significant deep shipwrecks in Australia and New Zealand, including one in 2002 which was the deepest wreck dive undertaken at the time. He was conferred Fellowship of the Explorers’ Club of New York in 2006, and was the Rolex Diver of the Year in 2015. His most recent expeditions were the Pearse Resurgence cave exploration (New Zealand) in February 2020, a project to take arterial blood gas specimens from an elite freediver at 60m in January 2021, and hunting a shipwreck in sub-Antarctic in February 2022.

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Dive Log Australasia #410 February 25

The Australasian Diving Safety Foundation The Australasian Diving Safety Foundation (ADSF) is an Australian-based Health Promotion Charity. The main object of the Foundation is to “promote the prevention and control of diving-related diseases and illnesses in human beings, including but not limited to decompression illness.” The ADSF supports its objects predominantly by undertaking research, providing education on diving safety, and offering grants for relevant research, diving safety promotions, dive medical training, oxygen equipment and AEDs. Funds have been allocated to support up to AUD$150,000 per year for appropriate research projects. In addition, the ADSF offers grants of up to AUD$20,000 to fund safety- related projects within the diving industry. Full details of these grants, as well as applications are available at http://adsf.org.au.

EDITOR’S COMMENTS JOHN LIPPMAN’S RESEARCH. COMPRESSED GAS FATALITIES I magine that you had died on a diving accident. Wouldn’t it be great if you could wind back the clock just for the brief moment and nip that tiny decision or mistake in the bud and get another chance at life? Exactly the way we did as children playing ‘wars.’

So many fatalities in diving arise from making the absolute tiniest of mistakes! As we all know, things have a nasty habit of compounding rapidly and a tiny mistake can have the absolute worst outcomes. I have taught more than one thousand divers over two hundred full scuba courses over many years so I have seen a lot of what could go wrong. On the other hand, a good dive instructor absolutely never has to experience anything near the more serious diving accidents. They are extremely vigilant, have systems in place to minimize problems and are able to watch their students carefully at all times. Any and all problems are nipped in the bud and managed well before they escalate. If your diving instructor is having to perform full blown rescues, they have let a small problem go too far and beyond the point of no return. They need to reassess their management and teaching methods. On one occasion, I replaced the mouthpiece on one of my spare regulators and clamped the cable tie down. Months later, after it sat in my spare, save a dive kit for ages, I lent it to a friend who was very inexperienced. He must have done some ‘gorilla breathing’ and clenched his jaw on the mouthpiece so hard that the mouthpiece and regulator became separated at fifteen metres about twenty-five minutes into the dive. The cable tie had been ripped off with force. (He was a black belt in karate.) I saw him with a mouthpiece in place but the regulator had fallen out. He breathed in a mouthful of water. Luckily, we were employing the buddy system and I was aware that he hadn’t dived in a while so I had hold of his SPG as a precaution. Here is an example if a tiny mistake and its consequences.

I had maintained a direct physical contact without making him feel cramped for space for the entire dive. I spotted his problem instantly the reg fell from his mouth and gave him the Octopus immediately before assisting him to the surface. He was distressed but ok. This little anecdote serves to illustrate how a tiny, tiny thing can have the potential to be fatal. Some ‘What if’’s could be: If I was five metres away? When I was teaching diving intensively, I never, never ever chided a student for making a mistake. Instead, I always told the group on the post dive brief that this was a ‘solid gold’ opportunity to learn how to improve diving safety. I used to actually thank the student for creating a brilliant learning opportunity for all of us to learn from. A good diving instructor must be positive, supportive and above all teach their dive students as best as possible. Sadly, I have experienced dive instructors who take sinister pleasure in embarrassing learner divers in front of the entire class for making a tiny mistake and using comments like “You Fail!” When a dive instructor gets angry with a student on day two of a scuba course, she needs to get out of the sport and hang up her flippers. These people suffer from burn out and need to go climb a mountain or get another job. Sadly, this sort of unprofessional conduct is not uncommon. Let’s look into John Lippmann’s excellent research into diving fatalities so that we can learn from him extensive work. Naturally, I am going to over-simplify John’s detailed research due to the limitations of space and time. However, it is fertile ground to gain so much benefit especially if it has been a while since you refreshed your skills. That includes almost ALL divers.

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DIVE LOG Australasia #410 - February ‘25

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Some of the main causes of the ultimate disaster were as follows:

Another worse one is badgering a partner to do the course against their will. Students have to want to learn to dive. I always told student flat; Never force a friend to share your dive excitement against their will. Never try to teach a friend because of the danger of not knowing how to rescue them if something goes awry. (As it often will)

Untrained, Inexperienced, and sometimes “older divers”.

Around one quarter of the forty-two fatalities between 2014 and 2018 were extremely inexperienced or with very limited experience. On the other hand, two-thirds were described as experienced or very experienced, who often succumbed to a medical event. Fourteen were hunting food, six were undergoing training and included five students and one supervising instructor. Two were rebreather divers. Fifteen divers were separated from their buddies, at least four intentionally. Of the 42 deaths, only eleven were still with their buddy. The obvious conclusion is that the buddy system is a very good idea. About one third of fatalities occurred on or near the surface. The surface can be more dangerous than underwater, often due to prevailing conditions. I always insisted that trainee divers insert the snorkel into their mouth the instant that they surface. I frankly do not understand why some divers are against this extremely important safety equipment. Apart from saving a huge amount of energy on long surface swims, it saves your air supply and allows you to breathe in sloppy, windy conditions in choppy water. Well over half did not inflate the BCD. Some had equipment malfunction due to lack of service. At least two-thirds still had their weight belt on. Poor dive planning was evident in more than half of the diving deaths. eight died in dangerous sea conditions. Over ten died after losing their buddy One of the absolute worst-case scenarios is an Open Water Diver who has just been certified and is filled with absolute joy at the freedom of diving and the exhilaration of scuba. He insists on taking a friend for a ‘try dive’ to share the joy. With minimal experience and knowledge and no training in Diver safety rescue, it will likely lead to a huge disaster. There were eleven ‘Solo divers’ Poor dive planning

Some other general discussion points

Lack of fitness

Obesity and pre-existing heart disease were major factors in many cases. The average age of victims was nearly 50 years old. Pre-existing heart conditions (which are often unknown to the individual), obesity and increasing age, lack of fitness all lead to the suggestion that the medical assessment should include a “Fitness to dive’ test. It is recommended that all divers aged 45 years or older seek a diving medical assessment with a doctor who is trained in diving medicine. Diving has some quite unique heart stressors and most doctors are unfamiliar with the demands of the underwater environment. The absolute and paramount importance of the buddy system has arisen as a major factor in the prevention of dive fatalities. The ongoing practice of dive skills especially for long time divers in skills like ditching weights and self-rescue It is the reason that the BSAC system of practicing dive skills in a pool regularly is such a good idea. Imagine the few seconds wasted as it takes for a diver in distress to remember how to rescue their buddy. These fwe seconds could be the differnece between life and death. Naturally, there are so many other situations that I could discuss. If one diver reads this and gets some benefit and avoids a scary experience, then my time will be worthwhile. The vital issue is that all divers can benefit from reading John’s vital research and acting on it by revising skills and being more careful. John’s full paper can be read by copying and pasting the link below into your browser at: https://adsf.cdn.prismic.io/adsf/Z4IUU5bqstJ99VgA_Lippm ann_CompressedGasFatalities-2014-18.pdf

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DIVE LOG Australasia #410 - February ‘25

Swallow-Tailed Sea Slugs

An Assortment of Aglajids - Part 2 Not all of the aglajids have the long tails like most of those presented in Part 1 of this series. The examples shown here in this second part, do have tails, or caudal lobes, but they are of modest size and usually of almost equal length and somewhat paddle-like in presentation. As we move into these other genera the amazing diversity of appearance in this family is revealed. NudiNotes and the NudibranchDomain.org website does not split up Philinopsis into four separate genera as proposed in 2017. The taxonomy of Nudibranchs & Sea Slugs Identification - Indo-Pacific, Gosliner, Valdes & Behrens, 2018 is followed. All of those species still represent a monophyletic group. The separation (splitting) is considered unnecessary and simply adds to confusion. (Note: The sp. numbers refer to species on the NudibranchDomain.org website)

Above: Three presentations of Philinopsis speciosa , a highly variable species in colour and patterning. Most usually with a black background and blue edging, stripes of yellow or orange and sometimes with spots or patches of a lighter shade. Specimens of lighter colouration are known. A distinctive characteristic is the upturned posterior extension of the headshield. It is an aggressive nocturnal hunter of bubble-shell sea slugs.

Above: Two examples of the Odontoglaja genus - Left: Odontoglaja guamensis and Right: Odontoglaja sp. 01 Most aglajids do not possess a radula or gizzard plates however the Odontoglaja are the exception having radula teeth that can secure their prey and a rudimentary gizzard for crushing. Considered to have reached a peak in predatory specialisation in the hunting of highly mobile prey such as polychaete worms, isopods and other sea slugs.

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DIVE LOG Australasia #410 - February‘25

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Above: A species wide-spread in the Indo-Pacific, Philinopsis pilsbryi can appear in huge populations when conditions are suitable and yet be scarce at other times. From Left to right: A typical adult with the light and dark reticulate pattern; A close-up of the head showing the distinctive crest that houses its long folded and protrusible buccal bulb, right eye spot and the anterior lateral groove between parapodia and body that channels water over its Hancock sensory organ to the mantle cavity and gill; A juvenile of the species with its thin-lined reticulate pattern.

Above: Black or dark brown with blue edging, Philinopsis gardineri also exhibits a thin white line to the posterior edge of the headshield - just discernible in this image. The anterior crest is distinctively bubble shaped. Similar to Chelidonura varians in colour and pattern with the dark base and blue edging, but not possessing the long tails of that species/genus.

Above: The distinctive patterning gives rise to the name of Philinopsis lineolata . It presents with a light background colour with transverse black lines down the entire length of the body and parapodia. Variation in the width of the black transverse lines give a range of appearance as does a diversity of the lighter background colour from white to yellow.

Above: This specimen Left: could possibly be Philinopsis reticulata (Milne Bay, PNG). The patterning is highly variable in that species based on a dark reticulation over a lighter background. Sometimes the reticulation is open and other times it is so tight as to appear more like spots. Blue colouration (purplish here) on the anterior inside edges of the parapodia and caudal lobes is also considered diagnostic. Right: Another specimen (Philippines) that could possibly be identified with Philinopis reticulata but would be an extreme variation. Currently listed as Philinopsis sp. 02.

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DIVE LOG Australasia #410 - February‘25

Above: Left: Philinopsis orientalis is dark with dense white spotting. There is a distinctive transverse white bar at the posterior end of the headshield that lines up with similar bars on the parapodia. These are raised with a central yellow spot and edged in light blue/green. Similar bars are located at the anterior of the headshield lining up with the anterior of the parapodia. There is another Y-shaped bar on the posterior of the posterior shield that runs longitudinally before flaring out onto the dorsal edge of the caudal lobes. Right: Most likely a variation of Philinopsis orientalis being similar in nearly every respect apart from its very light watery-orange colouration.

Above: Philinopsis falciphallus is a distinctive species in having its posterior shield terminated into a long conical blunt ended papilla that is carried elevated from the body. Its colouration is also distinctive, being gaudy with magenta to pink base colour with darker margins and numerous bright yellow/orange spots. Usually sighted when out hunting at night.

Above: Philinopsis gigliolii is another variable species with a range of colouration. The small lateral outgrowths of the anterior edge of the foot are observable in the above image. Philinopsis taronga has recently been synonymised with Philinopsis gigliolii . It has also been shown to be a good and separate species from Philinopsis speciosa .

Above: Three examples of the Niparaya genus. The members of this genus are all small usually less than 5 mm and possess a large triangular headshield with the posterior apex often held erect. They hunt in and out through the growth on the substrate, burrowing from time to time. From Left to Right: Niparaya sp. 12 black with white markings and orange stripes; Niparaya sp. 02 translucent with spots of opaque white pigment, black spots to the low parapodia; Niparaya sp. 13 translucent brown/orange with spots of opaque white pigment and yellow spots to border of headshield and on caudal lobes.

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The magnificent Jewell of Raine Island and Great Detached Reef text and photos by Mike Scotland

F or me, the ultimate diving playground on the Great Barrier Reef is Great Detached Reef, Raine Island. It lies up in the far North of Queensland close to PNG. about 120 Nautical miles ESE of Thursday Island. I have been lucky enough to have visited Great Detached Reef five times and have dived there 93 times. Great Detached Reef is a magical and unbelievable place to explore. There are few safe anchorages, many wild unexplored sites. It is so remote and far from civilisation.

We dived at a spot the skipper called Perisher Blue. It is a shallow, white sand dive to about 14 metres maximum. The scene from the boat was that hypnotizing clear, sapphire blue water that draws you in with a powerful urge to jump in and explore. As we dived in, the magical azure blue transfixed our senses and transported us to that serene state of exhilaration that we divers love. Time to lazily explore the islands of coral and meet the locals.

We circled around the dive site from one isolated bommie to the next. You could see your dive buddy twenty metres away. Most of the dive is less than nine metres. Besides, the dive site is a half moon area where you simply cannot get lost. I spot a few of the golden coloured Diagonal Sweetlip glowing brightly in the brilliant sunshine. Some of them were fearless and seemed to want to interact with me. There is nothing better than a

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DIVE LOG Australasia #410 - February 25

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