The owner of a boating rental service at the Galveston Yacht Marina called the Coast Guard Sector Houston-Galveston at 7 p.m. on Sunday and reported that a renter had not returned after departing at 2:30 p.m.
The caller said the missing man intended to visit the SS Selma and return before sunset. He's described as a white male last seen in a 22-foot center console boat with a blue top.
USCG Heartland tweeted a photo of what the boat looks like.
Coast Guard officials said it's unclear if the man was wearing a life jacket.
Boat crews and a helicopter crew searched for the man on Monday morning.
Anyone with information that may assist search efforts should contact Sector Houston-Galveston at (281) 464-4851.