Tabla de contenidos para 3/2018 en Scuba Diver/Asian Diver

Are we healthier and happier when we are around or in the water? There is an emerging school of scientific thought that supports this idea and the concept of the “blue mind”. This phenomenon is described as a mildly meditative state of calm unity, and a sense of general well-being that is created when humans are near or in water. This hardly comes as a surprise to those of us who dive and snorkel, especially when we do so at beautiful locations such as Wakatobi in Southeast Sulawesi, Indonesia. The phenomenon known as the blue mind was first popularised by marine biologist Dr. Wallace Nichols. After devoting much of his career to sea turtle research and conservation, he shifted his focus to the study of what he feels is a…

The axolotl is a unique species endemic to Mexico, capable of regenerating almost every part of its body. Thanks to this unique ability, it has become one of the most studied species in the world. The axolotl is a type of salamander that uniquely spends its whole life in larval form. It is the only species that never undergoes metamorphosis. As they age, axolotls simply get bigger and bigger, like amphibious Peter Pans. Unfortunately, the number of axolotls in the wild has dropped dramatically through the years, and they are now considered critically endangered by the International Union for Conservation of Nature (IUCN). The main threats they face include habitat loss, water contamination by industrial practices, and the presence of invasive species in their habitat. The long-term survival of the…

Sixteen million years ago, in the northern-most region of the Earth, a land of fire and ice first appeared after a fissure in the Mid-Atlantic Ridge created a volcanic hotspot that gave birth to this landmass. Here, the North American and Eurasian tectonic plates meet, continuously diverging and expanding the land area by five centimetres each year. Active volcanoes, geysers, glaciers and geothermal areas populate the island. Because of its dramatic topography and geographical location, almost 80 percent of the country is uninhabited, with only 330,000 people living in Iceland today. Inspiringly, all of Iceland’s energy is produced via geothermal and hydroelectric power, with 90 percent of households heated by geothermal water. The land offers plentiful natural resources that Icelanders have harnessed to produce renewable energy. Iceland’s underwater sights are…

KONA & THE BIG ISLAND, HAWAII Manta alfredi Peak Season: Year round Population: <350. Main attraction is the night dive/ snorkel with mantas off Kona REVILLAGIGEDO ISLANDS, MEXICO Manta birostris Peak Season: Year round (best Nov-Jun) Population: >350 but expected to be much larger. This location consistently has sightings of very large individuals with wingspan >5m. Black mantas are also common at this site ISLA MUJERES & ISLA HOLBOX, MEXICO Manta birostris Peak Season: Year round Population: Unknown. This Caribbean manta could well be a third species of manta ray ISLA DE LA PLATA, ECUADOR Manta birostris Peak Season: Year round (best Jun-Oct) Population: ~350 but expected to be much larger. Weather conditions make this site hard to access at certain times of the year MALDIVES Manta birostris Manta alfredi…

ANATOMY OF AN EAR The ear is the organ of hearing and balance. Understanding its anatomy can help better illustrate why it’s essential to equalise. The ear consists of three distinct spaces filled with either air or liquid: the external, middle and inner ear. As divers descend in the column of water, environmental pressure on the body increases in a linear fashion across the body. DISCOMFORT SCALE To prevent pressure-related injuries such as bleeding, 0edema (swelling) of soft tissues, leakage of fluid into the air space and membrane rupture, divers must actively enable air from the throat to enter through the eustachian tubes into the middle ear by using equalisation techniques. WHY YOU MUST EQUALISE AT 1 METRE  The water pressure outside of your eardrums is 10 percent greater than…

SATELLITE TAG STUDY REVEALS PHILIPPINE WATERS ARE INCREDIBLY IMPORTANT FOR ENDANGERED WHALE SHARKS A new scientific study has tracked juvenile whale sharks across the Philippines, discovering that all the subjects stayed within the country’s waters over the one-year tracking period, emphasising the importance of the archipelago for the species. By attaching Wildlife Computers SPOT5 satellite tags, researchers from Large Marine Vertebrates Research Institute Philippines (LAMAVE), Marine Megafauna Foundation (MMF) and Tubbataha Management Office (TMO) were able to follow the movements of juvenile whale sharks in near real-time to gain an insight into their behaviour. The tags work by communicating with passing ARGOS satellites, transmitting a location whenever a tagged whale shark breaks the surface. The study is the most complete tracking study of whale sharks in the country, with satellite…

Arguably, divers have never been at the forefront of a rescue mission of this magnitude before. This operation had a global audience gripped in suspense as international and Thai Navy Seal divers performed a search-and-rescue mission for the 12 missing boys and their football coach. With all 13 individuals safely evacuated from the cave, the hugely successful rescue mission has brought great attention to the diving industry – cave diving in particular. The crisis saw divers from all over rallying together to offer their expertise. In particular, Ben Reymenants, owner and founder of Blue Label Diving, was one of the first divers to be called onto the scene. Ben recalls, A friend and technical diving colleague of mine asked if I would like to go over and assist, as the…

“It is a dream-like experience to be submerged in the ocean. Breathing underwater, we visit a realm to which we do not belong. Everything is different below the waves; the way we move, the way we feel, how we hear, and especially what we see. The vibrant colours, diverse textures and unique patterns of marine organisms are something beyond even the wildest imagination. These characters in our underwater dream take on unusual shapes and display a palette of colours. The stripes, polka dots, and unlikely blending of hues are so astonishing that sometimes the canvas of a fish is as appealing as an artist’s masterpiece. “Perhaps it is that dreamland that we seek when we descend into the blue. Diving is considered an out-of-body reverie, and we strive to be…

Using a reef hook to lock into a rock in the midst of a massive current while dozens of pelagic animals drift by is an ethereal experience: Close your eyes and the passing rush of water gives the sensation of skydiving. Reef hooks are a necessary tool for diving current-ridden destinations such as Sipadan in Malaysia, Komodo in Indonesia, Palau in Oceania, and Donsol in the Philippines. But if you’ve never used one before, deploying a reef hook in current-coddled conditions can be a bit challenging. WHAT IS A REEF HOOK? Dive lore has it that the reef hook has humble beginnings in the Micronesian nation of Palau. Dive guides were looking for a way to decrease exertion and increase safety on the famed Blue Corner dive site, which features…

There is nothing quite as exciting as a fluorescent night dive. The ocean truly comes to life after dark, and it’s not just corals that glow: Some eels, sharks, stingrays, fish, and turtles also have fluorescent pigments. But being a coral communicator, my favourite organism to observe is always corals, and there is some pretty interesting science behind the glow. HOW DO CORALS FLUORESCE? Corals get their colours in two ways. They have photosynthetic marine algae living inside their cells which convert sunlight into energy. The brownish green colour you see in corals under normal daylight is from these algae, called zooxanthellae. When corals are bleached, they turn white because they expel the zooxanthellae. But then there are the blues, greens, purples, and reds which come from a family of…

Situated in the centre of the largest developed coral lagoon in the Maldives, a semi-submerged tidal gallery space has become a protective space for Nature to colonise and seek refuge. The Sculpture Coralarium, conceptualised by artist Jason deCaires Taylor, is the world’s first semi-submerged art gallery, requiring visitors to swim or snorkel to enjoy it. The cube-shaped building has its front façade submerged up to a median tide of three metres. The design of the walls is based on natural coral structures, with its porous design allowing the tides, current and marine life to pass through it. Inside the structure, 14 sculptures can be found; some completely submerged, others high above the waterline, with the majority hovering in mid-water, interacting with both the marine and the terrestrial world. It’s almost…

Sadly, within the first four months of 2018, there have been at least three fatalities of divers/snorkellers caused by collision injuries from boat propellers; one each in Thailand, the Philippines and Indonesia. It is likely that there are additional incidents, as many injuries often go unreported. These figures are of great concern to DAN and should be of concern to all divers. We felt it was timely to revitalise a safety campaign that focuses on creating awareness of propeller safety. Propeller injuries are unfortunately far too common in diving accident reports despite often being preventable. Many propeller incidents occur in remote locations where the medical facilities available to treat injuries sustained may be insufficient, and the licencing and regulating of boat drivers may be poorly enforced or does not exist.…

Though small in size, the nudibranch has made a pretty big name for itself. Nothing but a mere sea slug, this little creature has captured the hearts and cameras of divers around the world with its incredible diversity. To date, there are more than 3,000 known species of nudibranch, each with a unique pattern, colouration, and shape, attracting the interests of expert underwater photographers worldwide. You may think that the nudibranch would make an easy photographic subject, given its slow nature and vibrant colours, but this little slug has been a challenge to capture for even the best underwater photographers. It’s tiny size and habitat choice of sand and muck pose a challenge for photographers who wish to capture their striking features. Apart from their show-stopping appearance, nudibranchs also have…

On an atomic level, the fluorescent molecules of an organism absorb the tiny light particles, photons, of an external source such as a blue or UV light. The electrons in the fluorescent molecules are excited by the photons and they are “bumped up” to a higher energy state. When the electrons decay back to their normal state, a photon of lower energy and longer wavelength is emitted, which manifests as different colours.…

Underwater, Barren goes from long, seemingly empty, black sandflats to near vertical drop-offs covered in massive gorgonian fans The first islands in the Andaman chain to witness a new day dawning are India’s two volcanic islands – Narcondam and Barren. These two sentinels stand alone, further eastward into the Andaman Sea, with Thailand being the next great landmass 500 kilometres away. Barren and Narcondam are located along the north–south trending volcanic arc extending between Sumatra and Myanmar, with Barren still erupting to this day. The two volcanoes are isolated mountains in the Andaman Sea, with the foundations of Barren Island resting more than two kilometres below sea level. It is only natural, therefore, that both the active Barren Island and the dormant Narcondam Island have aroused curiosity and a sense…

REPORTED STORY We were on the third day of a trip that involved two dives a day at an island resort. This was the first dive in the morning. It was a normal dive: We spent less than a minute at 30 metres, and the swim-through exit was at 29 metres. I spent about 10 minutes at 24 metres, then another 15 minutes around 18 metres. I made a slow ascent with a three-minute safety stop at five metres. After surfacing, I experienced: • intense bilateral shoulder pain; • arm to fingertip pain; and • tingling and numbness in both my legs and toes. Fortunately, there was oxygen on the dive boat, so oxygen first aid commenced fast and I was able to keep breathing oxygen on the drive to…

Q: My students asked what happens to the nitrogen bubbles in untreated decompression sickness (DCS). My guess was that they eventually get reabsorbed or offgassed via the lungs. What is the best answer? A: Divers accumulate nitrogen (and/or other inert gases in their breathing mix) while diving. The deeper and longer the dive, the more gas accumulates. In cases of DCS, the inert gas load exceeds the tissues’ capacity, so bubbles form. Gas enters the body through the lungs, moves into the circulatory system and then into other tissues. Offgassing occurs by the same mechanism in reverse: Inert gas moves from the body’s tissues into the bloodstream and then into the lungs, where it is exhaled. A diver offgasses when in shallow water after having been in deeper water (during…

PASSIVE Requires no effort. Occurs during ascent VOLUNTARY TUBAL OPENING Try yawning or jaw wiggling VALSALVA MANOEUVRE Pinch your nostrils and gently blow through your nose TOYNBEE MANOEUVRE Pinch your nostrils and swallow (good technique, if equalisation is needed during ascent) FRENZEL MANOEUVRE Pinch your nostrils while contracting your throat muscles and make the sound of the letter “k” LOWRY TECHNIQUE Pinch your nostrils and gently try to blow air out of your nose while swallowing (think Valsalva manoeuvre meets the Toynbee manoeuvre) EDMONDS TECHNIQUE Push your jaw forward and employ the Valsalva manoeuvre or the Frenzel manoeuvre PRACTICE MAKES PERFECT Divers who experience difficulty equalising may find it helpful to master several techniques. Many are difficult until practised repeatedly, but this is one scuba skill you can practise anywhere…