Three children died when they became trapped underwater Wednesday night.
Attorney James Mercante says owner Kevin Treanor was on the 34-foot Candi 1 when it capsized but wasn't the operator. The lawyer says an insurance company hired him to represent Treanor.
Telephone calls to Treanor's home and work telephones have gone unanswered.
Authorities say the cause of the accident is under investigation. Safety experts say the yacht was overcrowded.
Officials hope to raise the yacht from 60 feet of water on Friday.