RedactedNarrative: Vessel 1 was on plane cruising back to the dock. Operator heard a loud bang and then heard a clunking sound.  The vessel came to a stop. The operator looked and could see water coming into the boat at a fast pace. The operator had his passenger and himself put on a PFD. The Tow boat arrived on scene and pumped the water down and towed the boat back. It was then determined that the U-joint in the out drive broke and was allowing water to come into the boat, swamping the boat.