If all snakes can swim, then this one beats the record. The sea snake lives almost all the time in the water, coming up for fresh air every hour or so. They prefer warm coastal waters and can be found in Pacific and Indian Ocean. This species belongs to Cobra family, and there are about 50 different types.
Some publications list the Belcher's Sea Snake as the most venomous snake in the world. With a quarter of a bite containing venom, a few drops can kill as many as 1,000 people. Although they are docile reptiles, fishermen are often bitted when pulling the nets out of the water.