Characteristics - Swimming Secrets
Like all members of the cetacean order, whales are propelled through the water by their powerful tails. The flippers are used almost entirely for steering and balance. The main propellant muscles are located along the upper side of the spinal column. These muscles pull a pair of broad horizontal tail flukes upwards against the resistance of the water in the power stroke. A set of smaller muscles along the lower side of the spinal column returns the flukes in the less forceful downstroke.
An additional boost to locomotion may come from a system of dermal ridges that exists under the smooth surface of cetaceans' skin. These ridges probably channel the flow of the water, helping to move a whale's body forward.
Streamlined for fast movement, whales' swimming speeds vary according to size.
Marine biologists calculate that some species are capable of speeds up to 35 miles
per hour (30 knots).
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