They are also attracted to fast moving objects, such as divers towed behind boats. Underwater World Perth has one of the biggest species of sea snakes found called Astrotia stokesii, which has an average length of 103 to 141centimetres with a maximum recorded size of 200 centimetres. This particular sea snake, a fish eater, is found in turbid coastal waters and coral reefs. A. stokesii has a large bulky build and is a sea snake of 1.6 metres in length, weighing 3 kilograms and has a girth size of 28 centimetres. With the ability to dive to depths of 100 metres this reptile can remain underwater for approximately 2 hours depending on the type of activity the snake is doing.
Some species are unable to tolerate extremes of temperature.
The upper lethal limit for the sea snakes body temperature is 33 - 36 C. Sea snakes avoid high temperatures by diving into cooler water away from the surface when it is travelling in tropical regions. It is for this reason they are found on the surface during rain on cloudy days.