Water Adaptation
(Stormwrack, page 94, DnD 3.5)
[General]
You favor your aquatic elf parent and have developed the ability to breathe and move about in water easily.
Prerequisite
Aquatic half-elf
Benefit
You can breathe water as well as air. Your swim speed improves to 20 feet.
Normal
Aquatic half-elves without this feat cannot breathe water and have a swim speed of 15 feet.