Silent Venom

When a decommissioned submarine on its final voyage is diverted to a South Pacific island to pick up scientists working on a top secret project, the crew is horrified to discover that the subjects of their experiment (hundreds of highly venomous snakes) have been inadvertently released on board. And having strayed into North Korean waters during a naval exercise, they are now under attack from above and unable to surface. Now they must survive long enough to re-surface and get off the ship.