Controlled Respiration( Savage Species, p. 31)
You can stay out of water longer than you otherwise could.
Endurance (PH) , Time limit on how long you can remain out of water,
You can control your breathing so as to remain out of water for a longer period of time than you otherwise could. Double the normal time limit after which you must begin making Constitution checks to avoid suffocation. This feat does not allow creatures that cannot normally breathe air, such as fish, to do so.