WATCH: Incredible Coast Guard rescue after man adrift at sea for 30 hours

Bobbing alone in the ocean with only a life vest, circumstances looked rough for 37-year-old Joey Trevino after more than a day of drifting.

A day fishing in the Gulf of Mexico with his uncle and two friends turned sour when their boat sank. Fortunately the four men from San Antonio were all wearing life vests. Trevino, though, was separated from his party.

Trevino told ABC News that thoughts of his wife and kids encouraged him as the hours wore on, and an encounter with a friendly porpoise gave his spirits a little boost. He kept swimming toward ships that he spotted and screaming for their attention. Fortunately his screams paid off, and the ordeal has a happy ending: One of those ships called the Coast Guard.

Trevino was unhurt, and immediately upon entering the U.S. Coast Guard's helicopter he learned that the rest of his party was already safe.

Watch the video above to see Trevino's rescue after his incredible ordeal.