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Spectacular Dirty Thunderstorm Surrounds Erupting Japanese Volcano
Underwater with Sri Lanka’s sperm whales
The sperm whale may be one of the most successful animals in the ocean, boasting a global distribution that survived the toll of the 20th century, when whaling factory fleets took three million great whales from the seas. Now a newly identified population in the Indian Ocean is attracting the attention of scientists, conservationists – and soon, tourists, too. How will this whale weather the new storm of attention?
Every March, vast numbers of sperm whales gather in the deep waters north-west of Sri Lanka. My photographs are vivid evidence of a little-known population – all the more surprising since sperm whales are the largest active predators on the planet with males reaching nearly 20m (65ft) in length. As natural submarines, they shut down all their organs except for their heart and brain, and using their muscular tails are able to dive for up to a mile, spending up to two hours feeding on squid.
Sperm whales (Physter macrocephalus) may be huge, but they’re difficult to see, spending 90% of their lives in the deep. As vision is useless, they use sonar clicks to locate squid. The sound is amplified by oil in their heads known as spermaceti (once believed to be the animal’s semen, hence its common name) which has bio-acoustical properties. The result is the loudest animal noise in nature, able to stun or kill prey. But the clicks are also modulated for communication, in sequences known as codas. Audible over many miles, the sequences vary from one “clan” to another, like human dialects. Diving with the whales, I’ve often felt, rather heard, this deep interconnection – a sonic whale-wide web.
Last year I dove with a super-pod of 150 sperm whales here, many in mating mode. I watched a pair of whales swim belly-to-belly under our tiny fishing boat, so engaged in their coupling that they appeared blissfully unperturbed by the humans hanging a few feet over them. The young whale in the middle of this photograph is evacuating her bowels – not a great moment to be swimming behind a whale, as I discovered to our cost.
With eyes set either side of their heads, sperm whales have to turn upside-down, like this female, for a 3D view of us. But she may also be “presenting” herself, advertising her willingness to mate. The Sri Lankan gathering is a cetacean “spring break”. But it’s also a positive indication of the relative health of the global sperm whale population, estimated at 360,000, according to the scientist, Hal Whitehead.
Sperm whales began to evolve 25 million years ago; they now possess the biggest brains on the planet. They are defined by matriarchal culture, passed on from mother to calf; learned, rather than instinctive behaviour. Like other toothed whales, sperm whales act as “collective individuals”. Their loyalty can have tragic consequences, as the recent stranding of pilot whales in Australia shows.
Sperm whales strand too, but are too large to be rescued and are often euthanized to end their suffering.
We see these creatures through an anthropomorphic lens; as a landbound species, that’s the way that our culture tries to come to terms with theirs. They are mysterious selves, living in an alien world. Talking to scientists such as Whitehead, Luke Rendell and Shane Gero, I often feel I’m interviewing astronauts who’ve discovered extraterrestrial species. The wonder is the way we treated them. We “harvested” sperm whale oil for lighting, lubrication or cosmetics – the “cold cream” on my mother’s face when I kissed her goodnight contained spermaceti. Now we see the whale as emblem of a threatened planet, as if we were ready to build a new ark.
Placid by nature, sperm whales have no predators, apart from killer whales – and human beings. As the whale-hunters aimed their harpoons at the largest males, the species was genetically reduced in size. Historic sperm whale jawbones suggest animals of 80 or 90 feet in length were once common. We may no longer hunt this species, but we still have drastic effects on them. When 29 sperm whales stranded around the North Sea in 2016, large pieces of plastic were found in their stomachs. Organochlorines and heavy metals such as mercury, lead and chromium add to the toxic mix, as does the amount of sound we pump into the sea.
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Make The Most Of Your Aquatic Adventure
Before we talk about sea scooters, let’s talk a little bit about the human being as a swimmer.
The fastest swimming speed ever achieved (and recorded, at any rate) by a human being was 5.34 miles per hour. This record is held by the French swimmer Frédérick Bousquet, and is only a bit short of the 80 mile per hour speed of the black marlin, the fastest animal in the ocean. The average human in good condition with decent training swims at a speed not much above four miles per hour. Keep that in mind for later.
Recreational scuba dives seldom take divers deeper than 130 feet below the surface of the water. In fact, that depth — 130 feet or 40 meters — is a limit set by the Recreational Scuba Training Council. And that’s another number for you to keep in your head. (FYI, the world record for the deepest scuba dive is currently set at 1,090 feet down.) Snorkeling, on the other hand, occurs right at the surface of the water, with depth not a factor due to the short length of the average snorkel. And in case you were wondering, snorkels are short for good reason: the human lungs could not safely and reliably draw in air at its surface pressure at depths greater than two or three feet.
So we have established that most of us can’t swim faster than four miles per hour and aren’t likely to dive deeper than 130 feet under the surface of the sea. Those two statistics together mean that with a good sea scooter, you can basically enjoy a super human adventure.
Whether you’re living out your 007-inspired fantasies or you are simply trying to get some great pictures of a coral reef, a sea scooter is both an enjoyable and useful tool. When your arms and legs are freed of the burden of swimming, you can stay in the water for long periods of time without exhaustion or muscle soreness dictating the length and pleasure of the swim. And when you can zip along at speeds heretofore available only to Michael Phelps and the other Olympians, you can have a uniquely great time in the water. All you have to do is get a sea scooter. Or as they’re known in certain circles, a diver propulsion vehicle, or DPV.
Choosing A Sea Scooter
Sea scooters are not exactly cheap. In fact, even the least expensive model out there costs more than two hundred dollars. And while the lower priced models can still be plenty of fun, their speeds are on the low end, too. But their depth ratings aren’t that “low.” In fact, some sea scooters are only rated to go about 15 feet under the surface of the water.
On the other hand, the top-of-the-line sea scooters are fabulously expensive, running well into the thousands for highly rated professional models. If budget is no obstacle, then – by all means – splurge on a high-end sea scooter and make a splash the next time you go to the lake or the beach. These top quality models cruise at more than 4.25 miles per hour and can safely power you right down to 200 feet or more below the surface, the deepest depth you’re ever likely to see anyway.
For most of us, buying a sea scooter is the perfect time to take the middle road. For a few hundred dollars, you can have a great sea scooter. Now that’s far from cheap, but in this case, you truly get what you pay for. For double the price of the cheapest sea scooters, you can get a unit that cruises at more than three miles per hour, achieves depths of 100 feet, and offers a battery run time of an hour and a half at full charge.
Of course, if you’re just buying a sea scooter for some added fun in the pool (or for the kids, who might break it anyway), a low-cost model is a fine idea. Few pools are deeper than fifteen feet, anyway.
Using A Sea Scooter
Safe use of a sea scooter means not pushing yourself beyond your limits. Sure, a sea scooter can carry you far from shore with ease, but make sure never to stray farther from the coastline than you could swim back in if the unit dies on you. This is also true with depth: never go diving without a guide or partner until you are an experienced scuba diver yourself. Your body’s abilities and your experience set your dive’s depth and duration limits, not the specs of that sea scooter you’re using.
Most mid-range and high-end sea scooters allow you to adjust their buoyancy, and this is an important step if you’re going down to any serious depths. (If not adjusted for proper buoyancy, the sea scooter will be constantly trying to pull you back up as you try to go deeper.) Consult the unit’s manual and learn how to complete this task precisely.
Many units feature several gears, and just like with a car, the lower gears will give you more power but will also drain the battery more quickly. Toggle between gears as needed and enjoy a longer, smoother ride under the waves.
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