Waterspawn( Lords of Madness, p. 182)
Your abnormal body and heritage has become more pronounced. You have prominent fi ns and are supremely well adapted to the icy deeps.
Aberration Blood (LoM) , one other aberrant feat,
You gain a Swim speed equal to your land speed. This also grants you a +8 racial bonus on Swim checks, the ability to take 10 on any Swim check, and the ability to use the run action while swimming. You gain resistance to cold 5. You can breathe air and water with equal ease.