Charting interactions between dolphins and people
Most people who have been swimming with dolphins want to be able move faster and more easily though the water than we are normally able to, being the landlubbing creatures we are…
Seeing and breathing
Seeing and breathing
The first thing we usually add is a
mask and snorkel
, so we can see where we are going and breathe without having to lift our entire heads out of the water. Mammals such as whales and dolphins who have been living in water for millions of years have of course solved this problem without the need for gadgets. In the course of evolution, their nasal passages migrated from the tip of the nose or snout to the top of the head, making it easy to take a quick breath whilst surfacing; and they developed a muscular collar to seal off the external opening efficiently for diving. (Humans used to have ping-pong balls stuck in their snorkel tubes for this purpose, but nowadays most people make do without.)
Using a diving mask and snorkel we can swim comfortably at the surface, watch the fish and other sea life and spot a friendly dolphin as soon as it comes into our field of vision – instead of gazing into the sky wondering where he is, while bystanders on the shore shout “He’s behind you!” like a pantomime chorus. We can also duck-dive more smoothly from this position. Some people also use ordinary swimming goggles, but be careful not to dive too deeply with these as they don't have enough air space to allow safe equalisation of pressures so damage to the eyeball can result.
Back to Top
The second step is to get a pair of ‘
’, meaning foot fins or flippers, which represent a small step towards the broad tail of a marine mammal such as a seal or dolphin. Wearing fins is like having a long, broad, flappy foot and it makes swimming very much more efficient as we can use the largest muscles of our body, the thigh muscles, to propel ourselves through the water. A small movement from the hips is more effective than wiggling the ankles around and less likely to cause strains or cramps. Now you can forget about trying to pulling yourself through the water with your arms and make a more streamlined shape by leaving them by your side – just like sea-lions and seals do. In marine mammals, the front limbs have in fact become progressively smaller and stubbier, so that most modern cetaceans are now left with two small ‘pectoral fins’, which merely serve as steering aids. Propulsion comes entirely from the massive back muscles driving the tail up and down.
These photos show swimmers in full 'winter' kit with 7mm - 8.5mm suits consisting of longjohns with hooded jacket over the top, neoprene boots and strap fins.
Watching dolphins swimming underwater, it is obvious that the next step is to try and copy their smooth up-and-down motion. Of course this does not work at the surface, but once you dive underwater, it is more fluid and more efficient to treat your legs as one unit and allow your whole body to undulate as you drive your fins up and down. Even though our back muscles are weak compared with a dolphin’s, they can contribute something in this movement and the legs create less turbulence if moved together. Try the ‘dolphin-kick’ and see!
A logical progression from the dolphin-kick using ordinary fins is to get a
, a large one-piece triangular fin which has the added benefit of making you look like a mermaid if you are female with long hair. Only the dolphin-kick is possible with this fin. Getting in and out of the water and manoeuvring at the surface may be harder, and stronger leg muscles are needed to drive the bigger surface area, but once underwater you will really move. Monofins are hard to find in this country -
for the latest information.
Back to Top
Any warm-blooded animal entering the sea has to take special measures to keep its blood temperature around 37ºC while the colder water all around is busy conducting away any body heat. Cetaceans have a number of adaptions to solve this problem, including a large rounded body shape with a small surface-area to mass ratio, and a thick layer of fatty blubber just under the skin which provides insulation. Seabirds and furry mammals like otters trap air bubbles in their feathers or fur to act as insulation (which is why oil spillages kill them as the air gaps get clogged with oil and they freeze to death). Human beings cannot go very far down either of these roads, but can survive for a while in the sea by swimming actively so that the heat generated by muscular activity compensates for that lost to the water. The excitement of swimming with a dolphin can also make us put up with levels of discomfort we would not normally tolerate and even encourage us to over-ride warning signals of impending hypothermia. However, sooner or later it is time to get out and often a combination of shivering cold and exhaustion prevails when dolphin swimmers leave the water. This stage can be delayed, if not eliminated, by wearing a
, which is our equivalent of the dolphin’s blubber. Don’t feel bad, they need theirs too! Wetsuits work by trapping a thin layer of water between your skin and the suit, which the body soon warms up. Air bubbles in the neoprene make it an effectived insulator, so the sea is not able to conduct your body heat away so readily. The thicker the suit, the warmer it is, but a good close fit is essential for any wet-suit to work. Usually wetsuits are 3-5mm for occasional immersion such as when surfing or windsurfing, 5-6mm for summer snorkelling and 7-8mm for year-round snorkelling and diving. Suits for surfing and kayaking are usually one-piece, while diving suits usually have a separate jacket so you get a double layer of insulation around the torso, and a fitted hood as well. A compromise has to be reached between warmth and convenience as the thicker suits make it harder to flex the joints. Wetsuits are improving all the time and for summer swimming at least, the newer types of surfers' suits with a 5-4-3mm pattern, 'titanium' lining and possibly a thermal undersuit and hood offer a good combination of warmth and comfort.
Back to Top
More of a problem with a thick neoprene suit is the buoyancy created by all those air bubbles. We are already positively buoyant at the surface and now we have added the equivalent of about a tenth of our body weight of extra uplift. Once we get down deep enough, the water pressure will compress any air spaces whether in our lungs or in a wetsuit, and we will be neutrally buoyant again, but the problem is getting there. The solution is crude but effective: a
with lead weights on it. How much to use is a matter of trial and experience. Again, if you use too much, the weight can slow you down, but with too little you still bob back to the surface too easily. With a thinner surfer's suit you won't need weights at all.
It is worth persevering even though all this gear feels strange at first, as you get a much better feeling of being in the dolphin’s world even when you can get just a few metres below the surface.
Back to Top
One man who has got closer than most to feeling himself into a dolphin’s body is Dutch sculptor and dolphin enthusiast Jan Ploeg. Making his own monofin was not enough for Jan; he also hand-carved a wooden ‘waterwing’ to simulate the dolphin’s pectoral fins. The latest addition to his dolphin-swimming wardrobe is a strap-on dorsal fin.
Jan swims with Dusty regularly and says that Dusty loves his unusual accessories. Check out his reports on his website at
Back to Top
Powered by WebPilot
| Subscribe to our Newsletter
| Contact Us
| About Irishdolphins.com
© 2001-2007 IrishDolphins.com