What is the fastest underwater creature?

Question

How fast can it move, and for what duration of time?

Answer 1

The sailfish can reach speeds of 68mph when leaping through the air.

Answer 2

The Sailfish is the fastest animal in the sea.  It can reach speeds over 60 MPH, if you can imagine that.  It can maintain this speed for quit awhile. There is yet nothing made by man that can even come close to that speed underwater.

The fastest land animal is the Cheetah, reaching speeds up to 80 MPH.  But, only for short bursts.

The fastest insect is the Dragonfly, which can fly through the air as fast as 35 MPH for as long as it wants.

The fastest running ground insect is the Cockroach.

The fastest animal in the world, is the Peregrine Falcon, which can dive at 250 MPH, from great heights in thousands of feet, and will maintain this speed for as long as it takes to reach its prey target (flying bird).