DIVE LOG DECEMBER 25 ISSUE 415

DECEMBER 2025 | No 415 digi tal

AUSTRALASIA

www.divelog.net.au

SPOTLIGHT BY KEVIN DEACON FIJI DIVING LIFE ALISON SMITH FREE UNDERWATER PHOTOGRAPHY COURSE CH 3 FISH PHOTOGRAPHY MIKE SCOTLAND HERON ISLAND DIVE FESTIVAL ORGANISED BY DIVE LOG AUSTRALASIA KICKER ROCK, GALAPAGOS KEN HOPPEN

new

PURSUE PERFECTION HYDROS PRO 2 BCD

heavy-duty, quick-dry bladder

enhanced control

advanced monorail weight system

scubapro.com

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MODULAR FIN SYSTEM BY SCUBAPRO The ability to change anything, changes everything. Take max power to the next level with SCUBAPRO’s Modular Fin System. Choose from the Seawing Supernova or S-Tek blades in multiple colors and a full foot or boot-fit foot pocket to assemble your perfect fin. SCUBAPRO’s Modular Fin System (MFS) goes beyond personalization. This high performing fin offers a range of interchangeable components allowing you to optimize your fins for your various dive conditions and add personal style and color. It starts with foot pocket selection, open heel to wear with boots and full foot to dive barefoot. Next, choose your blades. The Seawing Supernova offers maximum speed, power, and maneuverability in a variety of colors, while the S-TEK blade is designed for precise alternate kick control. The two-piece design saves space in your bag. SCUBAPRO’s Seawing Supernova Blade represents the next generation of powerful SCUBAPRO fins. Winner of the prestigious, internationally-recognized Red Dot Award for product design, the Seawing Supernova is a step up from the Seawing Nova in performance, construction, fit and versatility. The proven Pivot Control Technology (PCT) works in tandem with the unique Auto-Adjust central panel to always provide the optimal angle of attack for the blade.

The PCT hinges pre-set the blade in the 40º to 50º range that is ideal for converting kicks into forward motion. The flexible Auto-Adjust central panel then fine-tunes the angle of attack according to the strength of kick by counterpivoting, providing a milder angle of attack for comfort when kicking gently, a more aggressive angle of attack when kicking at full strength, and anything in between. When it comes to frog and alternate kicks, the new twin-tip winglets increase control and markedly improve maneuverability. Made of premium Monprene for maximum durability, the Seawing Supernova’s innovative two piece design, with blade and foot pocket molded separately, makes transport easy. The Seawing Supernova Blade is the go-to blade for avid recreational and professional divers seeking maximum speed, power and control in all diving conditions. Foot pocket sold separately. Complete open heel fins in Black and white: AUD$391.00 Complete S-tek Fin Open Heel: AUS$404.00 Full Foot Pockets in Black and White: AUS$85.00 Optional color Blades (Pink, Blue, Yellow, Turquoise) : 170.00 AUS$ Fo more info, go to https://scubapro.johnsonoutdoors.com/us/shop/fins/modular

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

rest5ft

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

We have been told that there is a great loss of bio-diversity all across the planet. This is in every ecosystem in every continent. We have been told this again and again and again for centuries. The co-conspirator of Charles Darwin, Alfred Russel Wallace wrote about deforestation 150 years ago and about the consequences of forest destruction. Divers see every marine ecosystem is severely out of balance. Sea Grasses, sea weeds and Insect populations across the globe has shrunk to less than half of what they were just sixty years ago. Same for birds, mammals, fish, whales, everything. We are destroying our home! Plankton in remote oceans like the Alaska seas are depleted. Professor Michelle Hoffman joined an Expedition to record an alarming report by the University of Alaska in Dive Log 390. Sydney’s Fish stocks are less than 5% of the 1960’s population. The report card for humanity’s role in caring for the planet is a dismal FAIL. Frankly, the human race needs a big kick in the pants to wake them (us) up. We can fix this easily. It is called gardening! What if…. If every country in the world planted a billion trees a year. If everyone grew something. If every country in the world would set aside 30 to 40% of its marine areas as absolute no-take marine reserves, a whole series of miracles would happen. They would happen quite quickly in just a few decades. Paradise lost, Paradise regained. Fish stocks would recover significantly within 5 to 7 years depending on the breeding cycles of each species. So many species would claw their way back from the brink of extinction. Fishers would discover that their livelihoods would be vastly improved. Fish stocks build up; sad memories of empty net hauls would fade. They would be delighted with the outcome, the newfound abundance, just like it used to be; and should be. For those of us that observe Nature,this is easy to understand . One of the greatest driving forces and energy in the universe is the ability of life to proliferate. Mother Nature has the ability to regenerate, to rebuild, to restore, to overpower the forces of destruction caused by endless exploitation and consumption of all three main lifeforms. The take, take and take whilst giving nothing back has to stop! All GAIA needs is for humanity to give her a helping hand so that the life force rebuild the Garden of Eden. Humanity does do this to a degree but we do need to redouble our efforts and do a lot more. Plant a tree, clean up rubbish, don’t use toxic chemicals; set aside marine reserves. Stop overfishing. Stop dumping toxic waste into the sea. Anyone and everyone who plants a few trees in their backyard can observe the miracle of Mother Nature slowly, quietly and steadily growing like magic. The trees provide food and shelter for countless lifeforms, birds move in, life proliferates. It is the miracle of life! Everyone craves close contact with nature and its lifeforms. Steady cycles of flowering plants fill all of the days. You get to smell the roses. I have a rainforest in my backyard and a large garden in my front yard. My ¼ acre block is alive. It does not have Net Zero. It so Net Positive. It is a balanced ecosystem with so many billions of lifeforms. I have millions of Talitrus and Slaters that feed on compost, (the only marine sand flea and isopods that lives on land in your compost), compost worms, Kookaburras, Crested Pigeons, Ravens, Magpies, Currawongs five types of Parrots. We had four Tawny Frogmouths in the front yard. It is a living suburban oasis. Lots of people do this. Advocates of compost farming tell us that if half of the world’s YOUR COVER PHOTO Kevin Deacon’s photo of Cherie and the Ships Telegraph on the Fujikawa Maru, Chuuk Lagoon.

agriculture turned to composting their farms, the soil would contribute up to a massive 30% towards Net zero climate by 2050 by storing carbon products in the soil as humus for decades. Then, the farm productivity would improve, we could wean ourselves off deadly pesticides like Roundup. Imagine if we used the oceans as a garden on an industrial scale. This is happening in Aquaculture in a small way. If we plant massive areas of sea weed and coral; cultivate more fish farms and release a percentage back into the wild. Create 30% marine parks and stop illegal fishing using effective policing. We could stop massive corporations raping and pillaging fisheries until the sea is empty. There is hope and many scientists are working on finding ways to help the ocean recover from endless overfishing and slaughter. Unfortunately, stupid governments defund CSIRO scientists and limit research. They forget that Science is knowledge and research by very clever people will find solutions to problems facing humanity. Clever politicians should increase funding ten-fold to solve the planet’s problems. The main point is that there is hope. We know the problems so we can set about fixing them as a matter of urgency. Dive Log is launching the HERON ISLAND DIVE FESTIVAL next year. The dates are June 20 to 27. The festival is all about celebrating the fabulous marine life of the Southern Great Barrier reef. I have dived all across the Pacific Ocean and more than fifty extended dive trips to the Great Barrier Reef. I am in the very fortunate position to provide a balanced opinion based on observation and experience. Bin there , dived that… In short, the diving on the GBR is returning to its rightful position as one of the all-round best diving destinations in the world! A big claim but it is true. It has got big fish, turtles and sharks! The Green zones have been protected from all forms of fishing. Fish stocks are increasing; corals are recovering; Professor Peter Ridd tells us that the GBR is in good shape. Research has found that as fish populations recover, coral growth improves. It is connected ecosystem. Healthy fish life helps to balance ecosystems in a superb feedback energy flow. The GBR has abundant populations of marine life. There is nowhere else I have been that has such healthy fish, turtles and marine mammals. Heron island has thousands of recorded rays and turtles. It had superb fish biodiversity with plentiful big fish. Diving here is as good as or better that most overseas dives. The December Dive Log is another magnificent blockbuster. The aim is to strive for excellence in U/W photography, educational editorial content and armchair diving adventures. My aim is to inspire and energise divers to dive, learn and marvel at the many marvellous marine encounters that can be found as soon as you enter the briny blue. Fortunately, most divers develop great passion and love of the ocean and are so enthusiastic about preserving it. Best of all it is free. As always, we ask you to share Dive Log with your diving friends so that the good news and good vibes in Dive Log can resonate across the universe just that little bit further. Dive Log Australasia would like to wish all of our readers a MERRY CHRISTMAS and a safe, healthy and prosperous New Year filled with peace. Accentuate the positive, eliminate the negative. Don’t worry, be happy and expect wonderful things to come your way. Buy your diving mates a copy of my books.

Mike

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Features CONTENTS

DECEMBER 2025

digital

N o. 415 NEXT ISSUE DEADLINE : Issue 416 February 2026 Advert bookings 12th Jan Artwork due 15th Jan Editorial material : 12th Jan

015 WAKATOBI A WORLD WIDE ROLE MODEL Mike Scotland 023 OUR BACKYARD by Dr Terry & Cathie Cummins 027 GALAPAGOS’ KICKER ROCK by Ken Hoppen 036 WALINDI and KIMBE BAY by Mike Scotland 045 HERON ISLAND DIVE FESTIVAL 054 SPOTLIGHT by Kevin Deacon 058 FIJI DIVING LIFE by Alison Smith 068 Ch 3 U/W Fish photography Mike Scotland. 070 HINTS and TIPS CAPTURING GREAT FISH SHOTS 081 BREATHHOLD SNORKLE by John Lippmann 085 SYED RAHMAN INDUCTED INTO HALL OF FAME 090 “ SOLOMON ISLANDS CAMEO by Mike Scotland

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

Mike’s Contact details: 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

45 Heron Island Dive festival 53 Spotlight by Kevin Deacon 58 - DAN News 64 - PAUL WATSON

07 - Mike Ball Expeditions 03 ScubaPro’s Modular Fin System 12 PNG Resort Listings 15 Counter Strike -David Strike 18 Historical Diving O RINGS Des Williams 20 - NudiNotes Behaviour David Mullins 35 Your Shot 36 Walindi by Mike Scotland 43 John Lippmann IPO Fluid in lungs

66 - In Deep - Simon Pridmore 84 - Underwater photo magazine 97 - Dive Boat Directory 104 Marine Bio book promo - 107 Vale Michael Menduno by David Strike

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Great Barrier Reef on the November

View from the Bridge Trevor Jackson - Spoilsport Skipper www.mikeball.com/blog

PHOTOS FROM SEPTEMBER/OCTOBER

The Premier Crew I recently had Fox Sports installed at home. For me, there’s nothing better than coming home from a trip and having all the previous week’s NRL games ready to go in the man cave when the boat gets in. Yep, a self-confessed NRL nut — and that, in turn, drives my darling wife nuts... but that’s another story. The other night, during one of the broadcasts, the panel was discussing how and why some teams perform brilliantly one year and not so well the next, even when there’s little change to the lineup. They started talking about something they called the “one percenters” — strategies teams use that can improve performance by up to one percent. Among these were post-game ice baths, flash dressing rooms, and perfectly mowed practice pitches. Then one of the presenters mentioned a recent study showing that a team’s performance is directly linked to their commitment to each other — and that a team focused on doing the best for the person beside them (rather than for themselves) performs up to 20 percent better than one full of self-absorbed individuals. Twenty percent! That’s more than you’d expect from big factors like coaching staff or pay packets. The team that does it for each other, does better! I was thinking about this concept the other night while reading through our onboard feedback forms. After every trip, we ask guests to help us improve by giving an honest appraisal of their experience. And the one thing that appears on virtually every form?

1st. Manny Katz

2nd. Jim Dvorak

3rd. Lucy Judd

Coral Sea & Great Barrier Reef! The Best Diving on the Dive with giant potato cod, explore deep walls, witness shark action at Osprey Reef.

“The crew were the best thing about the expedition.”

That’s not to say the food, diving, and vessel aren’t great — they are — but it’s the crew that gets the gold medal every time.

New Special Expeditions! Check out our website for details.

Ribbon Reefs Suited to both Divers and Snorkelers.

Now, you’ll find outstanding crews on dive boats all over the world, and North Queensland has plenty of them. But this crew, on this boat, has something special — the kind of commitment to each other that those Fox Sports presenters were talking about. They’ve got each other’s backs, and their commitment to excellence is second to none. As dive crews go, they’re this year’s premiers.

www.mikeball.com T: +61 7 4053 0500 E: resv@mikeball.com #spoilsportlive #mikeballdive

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

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“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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Up to one third of diving deaths are due to heart conditions, mainly in divers aged 45 or more.

Many of these divers were unaware of any problem.

Diving includes many stresses on the heart, including: immersion itself, exertion, breathing restriction, and gas changes in the body, among others. PREVENTION: Have your heart health checked by a diving doctor at age 45, or earlier if unwell.

Photo by Dave Bryant

Don’t dive if feeling unwell.

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The Australasian Diving Safety Foundation

The Australasian Diving Safety Foundation (ADSF) is an Australian-based Health Promotion Charity. The main aim of the Foundation is to reduce diving-related illnesses and deaths.

The ADSF supports its aims 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$250,000 per year for appropriate research projects. In addition, the ADSF offers grants of up to AUD$25,000 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.

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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

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

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“Stamp out Coccolithophores and Penguins” by David Strike

It might be the little things in life that matter, but it’s always the big things that get our attention.

Take whales, for example. Weighing in at a staggering 60,000-plus kilograms, (that’s about 132,000 pounds for the metrically challenged) the mighty Blue Whale is said to be the largest creature that the world has ever produced. And yet our knowledge of their habits (like that of all whales – including the smaller and more prolific Minke whale) is pitifully small and largely restricted to observations made by early whalers who hunted them almost to the point of extinction. Some years ago, Japan’s announcement that they intended to hunt both the Minke and Humpback whales for ‘scientific’ purposes, public opinion came out strongly in favour of the whales with most people expressing condemnation at such unnecessary slaughter.

“People get incensed about the de-forestation of the Amazon jungles, claiming that they generate a significant proportion of the world’s oxygen and that their destruction spells doom for the earth. They forget that more than 50% of the oxygen in our atmosphere (some sources claim 98%) comes from the phytoplankton in our oceans. That same microscopic plant that provides the food source for zooplankton which, in its turn, is eaten by larger creatures such as krill; the tiny shrimp-like creatures that form the staple diet for baleen whales like the Blue, Humpback and Minke whales. And a big whale can munch their way through up to two tons of the stuff a day. “Were you aware,” Krabbmann continued, “that hundreds of millions of years ago, when life on earth first began, the planet’s oxygen levels were as high as 35%! Now look at it; the oxygen content is down to just a little over 20%. If you want my opinion,” (I didn’t, but I got it anyway) “it’s all the fault of the whales and their practice of scoffing down tons of plankton.

That should read, most people apart from my mate, Krabbmann.

“Science and popular opinion seldom see eye to eye,” he said. “And when it comes to whales, the question that you should be asking yourself is: what are whales doing for the planet and the environment?

“With so many of those little coccolithophores and other members of the phytoplankton winding up

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inside the bellies of whales, it won’t be long before we’re all asphyxiated. The fact is,” he said, “that nobody seems interested in championing the cause of the tiny stuff, regardless of its importance.” Even for Krabbmann, (a person without equal when it comes to making two plus two equal five) it was a lousy defence of whaling; a stance that he attempted to justify by pointing out the impact that an oxygen-enriched atmosphere would have on diving. “For a start, divers wouldn’t need to be convinced that smoking was a health hazard and incompatible with good diving practice - anyone attempting to light a cigarette could kiss goodbye to their eyebrows; nobody would have to fork out extra money on a nitrox course – that’d all be covered in diving 101; there’d be a greater acceptance of mixed gases for deep diving; and the role of narcosis in causing diving ‘accidents’ would be reduced considerably. And then there’s …”

better read this report from a scientist who claims that some species of phytoplankton, rather than simply doing what plants do best and using the sun’s rays to turn carbon-dioxide into oxygen through photosynthesis - and then reflecting the heat back into space - actually absorb the rays and are contributing to the greenhouse effect and the planet’s warming.” “If that’s the case” Krabbmann said, in a typical about-face, “then we should be doing all that we can to protect whales and encouraging them to eat more, not condoning their slaughter. “Penguins, of course, are another matter. All of those black feathers soak up the heat. If they’re allowed to breed indiscriminately then there’s a very real risk that the Antarctic ice cap will start to melt, causing a rise in sea levels that’ll flood out the dive shop.” Sadly, Krabbmann, like many others, gives too little thought to the complexity and magic of life – and the importance of conserving it all.

“Before you get carried away”, I interrupted, “you’d

—-ENDS—-

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BOOK RELEASE: BUY YOUR SIGNED COPY OF THIS PUBLICATION ON SHARKS from mike@divelog.net.au

Diving with sharks is the result of many thousands of dives with sharks. It is a special publications for many reasons. First, it combines throughly researched information about sharks. Secondly, it describes the behaviour and personalities of sharks based on observation. Third, it gives insights into how to dive with sharks safely and to learn about their behaviour. It summarises many thousands of hours of research into an easy to read text . It is a great educational resource like nothing else which will instill an infectious love for sharks and an urgent drive to protect them. Sharks need to feel the love! The text covers anatomy, physiology, reproduction and

lifestyle of many species of sharks. it is a useful guide for marine enthusiasts, divers and snorkellers. Mike includes anecdotes which give insights into how sharks will react to you in the water. He describes in depth observations about their behaviour. Best of all, it features great photos collected from decades of dive travel across many countries that illustrate the anecdotes. There is even a great description of how to get better photos of sharks and how to overcome light issues. You can purchase this special book by contacting Mike at mike@divelog.net.au The cost is $40 plus p&p $9

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When Scuba Gear was Australian-Made by Des Williams

THE HUMBLE O-RING STORY To seal, or not to seal, that is the question?

Recently, I got to thinking about the development of the humble O-ring seal, which is such a vital component within the range of diving equipment of today, including demand valves, cameras, and torches. Today most seals used in diving are quality O-rings, which did not begin to make their mark in diving until the early 1950s. Before then, it was a choice between rubber or leather for making an underwater seal. When the standard dress diving helmet was introduced in the 1830s, FLAT profile, leather seals soaked in Neatsfoot oil were used and they remained in use for over 100 years. An Internet search of the history of the humble O-ring reveals that it was not until 1936 that the O-ring was invented by Danish-American Niels Christensen. Commonly associated with wartime innovation, production of the O-ring was ramped up during World War II, when demand for reliable sealing mechanisms surged, and the U.S. government acquired Christensen’s patent to support the war effort.

unusually cold temperatures before launch. Since then, material science, quality tracking, and rigorous testing have transformed how O-rings are produced and used. Today, O-rings support everything from oil fields and hydraulic systems to dental implants, beverage dispensers and diving apparatus. O-rings today are made from a large range of high-performance synthetic materials to handle extreme temperatures, corrosive chemicals, and complex

Siebe Gorman & Robison Helmets

mechanical requirements. They include: Aflas, Neoprene/Chloroprene, Ethylene Propylene, Fluoroelastomer, Fluorosilicone, Nitrile, PTFE, Silicone and Urethane/Polyurethane. But, I digress, so let’s get back to O-ring development in diving. In the early recreational diving years of the 1950s, leather seals were initially used between the demand valve (regulator) and the cylinder pillar valve. This was

The design was elegantly simple - an elastomeric loop with a circular cross-section, compressed between components to create a durable seal. Despite manufacturing processes having become increasingly sophisticated today, the simplicity of the design has stood the test of time. The importance of O-rings became tragically clear in 1986 with the space shuttle Challenger disaster, caused in part by a failed Dupont Viton O-ring that lost flexibility in

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acceptable, as in those days cylinder pressures were still only 120bar/1800 psi. However, O-rings were already beginning to make their mark in some countries where higher cylinder pressures were available. In the UK they were not widely used until the late 1950s/early 1960s. There was a mid-decade period when white-coloured flat profile polythene seals were used. Alas, they proved too soft and, at best, lasted for one dive only. That requires an explanation, after all these early seals were part of early sports diving history. The seals were punched out of sheet material; their surface was slippery to the touch. As a result, the circular metal surface inside the demand valve yoke tended to skid sideways as it was tightened. There was no chance of a second attempt as an off-centre indentation remained, and a new seal was required. The first job on receiving a freshly charged diving club cylinder for use was obviously to check the indentation. Even if it was central there was a good chance that it would not work. The usual problem was that the soft polythene had been compressed to its maximum when the yoke had previously been tightened. There was not enough thickness left to be further compressed to make a second seal. Again, the seal itself had to be changed, which presented a further problem. Being soft, on compression the seals expanded sideways and tightly filled the circular seal groove. The pointed tips of diving knives found a second

use: to prise the polythene out. Divers got to carry around their own necklace of white polythene seals. It is recalled that sales of these seals lasted about two years, before black polythene seals came into use. They were harder, and often as not tended to have a central ring groove that could be reused for a second dive. Their tenure was, however, short-lived when O-rings finally began to appear towards the end of the 1950s. Before the pillar valve design was changed to accept new demand valve designs, the earlier O-rings were a straight change-out for the polythene seals. As our picture shows, their cross sectional diameter was large enough to fill the original pillar valve groove. It is quite possible that 1930s O-rings were not initially used as pressure seals, as there may have been a type of rubber problem. The arrival of synthetics needs looking into now to enhance this brief overview of the O-ring story. Pressure O-rings need a hard and wear resistant rubber as the above list of synthetic materials indicate. All hail the humble, synthetic O-ring, we would be wet without it! If you would like more information about diving pioneers, contact the Historical Diving Society Australia-Pacific by email at: or visit our website or Facebook

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STAYIN ALIVE THE DEFENCES OF SEA SLUGS - Part 5 Passive Defences continued

Structural - Physical anatomical structures

retained the shell, or a reduced structure, or even just an external or internal remnant. This serves to cover and protect the vital viscera. Across all the sea slugs there are representations of the various degrees of that shell reduction or loss. The shell as a form of defence is self-evident. It is a hard structure into which the animal can withdraw for protection. However, as with all methods of defence, predators will, over time, evolve their

Shells Shells are probably the most recognizable feature associated with molluscs in general. While all of the many forms of the true nudibranchs lack a shell as an adult, having discarded the larval shell at metamorphosis, many of the sea slugs of the lower orders have

Above: Shells or remnants. Clockwise from Top Left: Bullina lineata has a bulbous shell into which the whole animal can withdraw. The thin fragile shell of Lobiger viridis covers the viscera of the animal like a cap but it cannot withdraw into it. Tylodina corticalis carries a flattened limpet-like shell that only provides overhead protection. This specimen of Tomoberthella martensi has autotomised its three sacrificial lobes and the gill is exposed but the thin internal shell is visible covering the viscera. DIVE LOG Australasia #415 -December ‘25 20 www.divelog.net.au

Caryophyllidia Caryophyllidia are specialised low tubercle structures of the some of the Discodorididae family of nudibranchs. These are borne on the mantle dorsum. They consist of an apical, knob like, cilia–carrying sensory organ surrounded by a ring or crown of erect spicules all covered by a thin layer of epidermis. Although thought to serve primarily in a sensory capacity their true function has not yet been ascertained. Because of their spiculose nature however there is no doubt that they also serve to make the nudibranch disagreeable to predators especially so in those where the dorsum is almost completely covered by them. Shielding and decoy processes Shielding and decoy processes are possessed by a number of sea slug types including some of the true nudibranchs that have exposed gills and rhinophores.

own methods of overcoming them. Against the shell, stronger claws for external crushing, gizzard plates for internal digestive grinding or a combination of mechanical rasping and acid secretions to bore a hole through the shell into the softer tissue are examples. This is not to say the shell is useless for the shelled molluscs have proven to be a resilient and successful group. Some molluscan shells have developed quite elaborate forms in the attempt to counteract predator advances. Spicules Spicules embedded in the flesh together with tough, stiffened bodies while not as robust a shield as a calcareous shell, do serve to make the actual ultimate goal of the predator, the exposed flesh of the prey, unpalatable. In some species the spicules are not arranged in any particular formation however in some they protrude from the dorsum on tubercles.

Above: Tough or spiculose bodies. Clockwise from Top Left: Halgerda batangas has a tough ridged body. Phyllidiopsis cardinalis has a tough pustulose body. Atagema ornata has unpalatable caryophyllidia on its dorsum. A close-up of the caryophyllidia of Jorunna funebris .

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The phanerobranchs especially, those nudibranchs that cannot retract their gill for preservation, have fleshy processes around or in proximity to the gill that act in a protective role. As well as providing a form of physical barrier they could also be serving in a decoy function by having a resemblance to, or an even more attractive appearance to the indispensable organs they seek to safeguard. The rhinophores of some are protected in a similar manner. Among the cryptobranch nudibranchs, the Ceratosoma and Miamira are unique in possessing protective gill structures even though the gills are able to be totally withdrawn.

As we will see in the chemical defences section, the flesh of many of these structures are taken a step further by incorporating distasteful/noxious substances that may deter a predator from taking a bite but certainly from taking a second bite. With regard to the aeolids with their non-retractable rhinophores, it might be the case that these are lost to the sight of a predator amongst a virtual sea of waving cerata. A primary purpose therefore of many of these extra-rhinophoral and extra-branchial structures could be considered sacrificial in order that the vital parts – the rhinophores and gills, are left in working order following a strike by a predator. Next issue: Chemical Defences

Above: Shielding/decoy processes. Clockwise from Top Left: Bornella anguilla has processes that protect the rhinophores and fine gills and even brightly coloured to act as decoys. The massive sturdy lobe of Aegires serenae protects the gills. Trapania tora has extrarhinophoral and extrabranchial processes that look more inviting that those they protect, as do all the Trapania . The giant posterior horn of Ceratosoma tenue protects the gills even though it can still retract.

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Our Backyard: Cairns Travel Blog 9:Article and photos by Dr. Terry and Cathie Cummins .

O ctober November - this is the time in the Far North of Queensland, Australia when the weather Gods gently turn the switch on the wind direction meter from a predominantly South-Easterly to a Northerly direction. It is also the time that there is a slight hint in all the calmness that we are approaching cyclone season. Nevertheless, in our opinion, it is the best diving time of the year. Calm seas and access to diving sites that are a bit trickier to get to when the Southerly winds dominate. In fact, when we are asked: “what is the best time to visit Cairns”, we always say October/November when it’s either brilliant or great, but slightly on the unpredictable side. So we stay at home and enjoy your backyard where travel time to our preferred dive vessels is just 15 minutes and shorter than it takes us to unload the Landcruiser of all the dive and camera gear for the 100 m walk from ‘The Pier’ car park to the Cairns Marina docks. We have written several blogs on our adventures on Mike Ball Dive Expedition’s: Spoilsport at this time of year but we also absolutely love making day trips with our mates on AquaQuest where Skipper: Burkie and Divemaster: Mario, really go out of their way to put us on the very best dive sites the day offers. In fact, the boats we choose are all staffed with professional, knowledgeable instructors, who tirelessly help us in and out of the water with bulky

cameras and the added weight of our solo diving gear. So it’s time to have our readers gain an insight into the fantastic day dives that can be enjoyed in our backyard: Cairns. October / November is also the time many things are just happening. Countless fish species are breeding, and the Reef Authority temporarily close all fishing, so our fish populations have a chance to restock. Sea birds are likewise very active, turtles are mating and nesting, and the coral is spawning. But what about the actual diving? At this time of year you can experience ocean conditions at their very best. We experience ‘glass-outs’ (i.e. lake type surface conditions) on some days with wind speeds down to 5 knots or less, while underwater 30m plus visibility is not uncommon, water the temperature is up around 28C, and you can see all you want to see in less than 20m of water. Amongst the many dive sites found, Norman, Saxon, Moore, Milne and Flynn reefs are the most popular and our favourites. These five reefs have multiple dive and snorkel sites with each having their own unique name like: Sandra’s, Troppos, Plate-Top, Caves, Turtle Bay, The Edge, Club 10, Clippers, Golf Clubs, Fishbowl and Three Sisters. Remember even on day dives you are going to be at least 28 nautical miles from the coast, and we can have strong currents at some sites depending on the tropical tides. Therefore, through their ‘duty of care’ and

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consideration for the wide range of abilities we see in certified divers visiting the area, some operators insist on divers being guided by a local diving professional. At the other end of the table, some allow solo diving, especially if you can prove you are highly experienced in local waters and don’t just have the card. Most of the day boats offer a choice of three 45-minute scuba dives or two longer dives at two different sites. Additionally, all the vessels also offer magnificent snorkelling for guests with a wide range of abilities. Between dives the crew typically serve an amazing smorgasbord lunch with lots of choices including special diet requirements. As one operator told us: “we put a lot of effort into our lunches as no matter how good the diving is, we will get a bad rap on TripAdvisor if the lunch is crap”. On the way back to port most of the boats are licensed to serve beer and a choice of wines. Of course soft drinks and snack foods are always available. But while out on the reef, drink alcohol and you remain onboard and for some that suits them fine. It is all about having a great day of your choosing, isn’t it? So your scuba gear is sorted and ready, and you’re looking around feeling relieved that’s all done. But being an underwater photographer brings on further challenges. Leading up to the dive day, you look at the weather forecast, the tides, the likelihood of a very clear viz day, or not! So do you choose a wide angle port for the underwater housing to take full advantage of a very clear day, or will it be a portrait or macro day? Decisions, decisions photographers must commonly make on which lens and corresponding port to put on their housing! As soon as you rig up for macro, guaranteed you will see that Manta Ray, Whale Shark, or Tiger Shark and of course Blue Spotted Rays, Moray Eels, Barracuda, White Tip Reef Sharks and Turtle encounters are very common.

Likewise, with a wide angle set up you will get frustrated at seeing those beautiful little box fish, an amazing variety of nudibranchs, whip coral blennies, etc. This is where my (Cathie) housing is fantastic. The wet lens available for my Nauticam housing allows me to switch to wide angle, or portrait or even macro while underwater. Meanwhile, I (Terry) am stuck with whatever the decision I make. That is, to use either my Nikon 105 mm Micro for portrait and macro photography or the 10 mm fisheye for super wide-angle. At the end of the day we both get some stunning photos and even better memories. After departing the dock around 8:30 am, enjoying complimentary coffee, tea and muffins, experiencing the mandatory safety briefings, maybe even taking a nap, the comfortable two-hour voyage to the reef seems to just fly by. On reaching the dive site you kit up. Tanks and weights are supplied, or even a full kit if you do not have your own gear. Then the fun begins and then there is that solo diving thing. We jump in together, do our own dive, meet at the safety stop at a predetermined time and egress the water together. This dive procedure provides a big case for solo diving certification, especially for serious photographers. We are not talking about swimming along with your buddy capturing the moment with a GoPro. We are talking about the type of photography that needs time to set up shots and will bore the living day lights out of any buddy that must stick around and just watch you do your thing. Meanwhile, the big question is: “who is watching your buddy while your head is stuck in the camera viewfinder”? Any photographer will know what we are talking about and a great reason to think that serious photography, solo diving and lots of logged dives do go hand in hand and are not mutually exclusive. If you want

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to know more about solo diving our friend Carlos Lander has written a book in the series: “Beyond the Diving Course”, entitled: “Mastering Solo Diving: Your Essential Guide” (available via Amazon). Because the options are virtually limitless, we will now talk more generically across the range of breath-taking day dive sites we have off Cairns and let our photos from this past season do most of the talking. Needless to say, our backyard has just about every species of Butterfly, Angelfish, Surgeonfish, Damsels, Emperors, Sweetlips, Triggerfish, Boxfish, Groupers, Trout, Parrotfish, Lionfish, Blennies, Gobies, Wrasse and Garden Eels out on the sand. These are always present, but less often we get really excited to find frogfish, seahorse and pipefish. My (Terry) favourites are the nudibranchs, various species of Anemonefish, the Giant Puffer and schools of Longfin Spadefish.

For me, (Cathie) I have always thought how blessed we are living here in Cairns. The amazing GBR at our backdoor. The day boats are always available to take us out to explore the amazing display of colour, coral and fishes. I was slow to get into photography, and once was the ’spotter’, finding everything! But my Nikon Z50 in a

Photo credit Mike Scotland

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Nauticam housing is now my dive buddy and we love getting out amongst it all! I may not be as good as I was spotting that elusive scorpion fish, that crocodile fish, etc., because I’m concentrating on being a solo diver, navigation, the camera selections etc. However, I find I’m really drawn to the big picture images, the drop offs, the walls, the close-up-wide-angle shots. There’s always a surprise out there, and that is where my set up is great. I’m even now starting to play with the camera’s video option. I also love chatting with the tourists who share their stories about how wonderful their day has been. How amazing and beautiful the corals are. Fish everywhere. It puts a smile on my dial, and of course, if I manage to capture them in a photo underwater, I’m able to send that memory to them. Finally, let’s talk about research and data. My (Terry) PhD thesis on the sustainability of scuba diving off Cairns in the GBR Marine Park gave me some very interesting insights as to why day trips to the reef are so popular. Obviously, there are two major types of dive excursions for certified divers offered out of Cairns: day trips on Evolution, AquaQuest, SeaQuest, Tusa, Reef Magic, Dreamtime, etc., and live-aboard experiences on Mike Ball’s: Spoilsport, Rum Runner, OceanQuest and Spirit of Freedom. While the day boat and live aboard offerings are distinctly different there is an apparent, and complex, cohort of certified divers that prefer day vessels to do multiple daytrips to the reef during a single visit to Cairns. I (Terry) ascertained through conversations with over 500 divers that this practice potentially gives them a break from the repetitive diving experienced on a live-aboard. This cohort feels it provides an opportunity to dive with different operators at a wide range of dive sites, have time-out to experience other activities (e.g. the Daintree, Bungee Jumping, Whitewater Rafting, Go-Carting, etc.), possibly with non-diving companions and the option to take breaks between dives to participate in the local night life (e.g. night clubs and the Casino). So the take-away message is don’t give up on exploring day dives when visiting not only Cairns, but other areas where fantastic day boats, live aboard vessels and other activities share the same space. Of course the very, very best option is to do a couple of day dives to warm-up for the often more advanced dives you will commonly experience on live aboard trips. Even with all our diving experience, when we travel up the big pond to say PNG, we will do day dives at Walindi Plantation Resort before jumping on Oceania or Febrina for 7 to 10 days at sea. This not only places an element of safety into an extended dive vacation but also gives you an extremely enjoyable variety of underwater experiences in one region. To find out more about diving opportunities off Cairns, right along the Queensland coast and onto our near neighbours in PNG and Fiji, please visit our website: www.dive-queensland.com We hope to see you out on our magnificent dive sites soon.

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