What is the fastest animal in the water?
The world's fastest animal in water is sailfish. Sailfish are two species of fish in the genus Istiophorus, living in warmer sections of all the oceans of the world. They are predominately blue to gray in color and have a characteristic erectile dorsal fin known as a sail, which often stretches the entire length of the back. Another notable characteristic is the elongated bill, resembling that of the swordfish and other marlins. They are therefore described as billfish in sport fishing circles.