Sea Legs

Gnome

Accustomed to being on boats and at sea they do not have any penalty to movement no matter how long they don't step on a boat.
A childhood spent climbing on costal cliffs and ship rigging has given you a climbing speed of 25ft.
Make all diving and swimming checks at advantage.
You gain a swimming speed of 25ft.
In addition, you can hold your breath for a number of minutes equal to tripple your constitution modifier (minimum 3 minutes).