Dolphins and tuna can swim so fast MAR 31 2008
When the bubbles [formed by cavitation] collapse, they produce a shockwave, which eats away the metal in propellers. To dolphins, it is painful. According to the researchers' calculations, within the top few metres of the water column, this happens when the dolphins reach 10 to 15 metres per second (36 to 54 kilometres per hour).
Tuna don't have this pain problem; their tails don't have nerve endings.