Using this skill, a land-based creature can swim, dive, navigate underwater obstacles, and so on.
Retry: A new check is allowed the round after a check is failed.
A successful Swim check allows you to swim one-quarter your Speed as a Move Action or one-half your speed as a Full-Round Action. Roll once per round. If you fail, you make no progress through the water. If you fail by 5 or more, you go underwater and must hold your breath with an Endurance check until you can reach the surface by succeeding on a Swim check. The DC for the Swim check depends on the situation: