Stevenson Weeks, the lawyer for Lady Mary owner Royal Smith Sr., said extensive damage to the boat's rudder, propeller and other equipment indicates that some other vessel crashed into it and kept going. Smith lost two sons in the tragedy.
Weeks said he based his suspicion on "the nature of the damage and the physics involved."
Weeks spoke during a break in a Coast Guard hearing investigating the March 24 sinking of the Lady Mary about 60 miles off the coast of Cape May. He said striking another vessel and leaving the scene can be a crime, just as it is in a motor vehicle. "If you can prove who did it," he added. "It's tough."
Since the hearing began in May, the Coast Guard has heard several theories regarding the cause of the disaster. Besides the possibility of an at-sea collision, the panel also heard the theory that the Lady Mary's gear may have become tangled on the ocean floor, or with another vessel.
As the hearing resumed Monday following a five-month adjournment that allowed divers to retrieve evidence from the wreck, a shipwreck diver testified about finding the body of one of the victims, Tarzon Smith, in the fish hold of the sunken vessel, covered with boards that were designed to separate the catch from the rest of the boat.
A survival suit, which protects against hypothermia, was found nearby, out of its packaging. Smith's body was clad in sweat pants and socks, no shoes.
"My assumption was he was trying to get into his survival suit," Capt. Steve Gatto testified. "You don't run around the deck in your socks."
Gatto also testified he found a 6-inch hole punched into the port side of the ship just above the water line, and noted the rear of the boat was damaged, with parts bent inward.
"It was crushed in really good," he said.
A key piece of evidence is likely to be the boat's rudder. It was recovered along with several other items over the summer by divers.
Gatto testified that the bent rudder was painted beige, but there was some red paint on its edge. That could suggest a collision with another vessel.
Also Monday, the captain of a Massachusetts fishing boat told of hearing a brief, panicked radio transmission, lasting less than a second.
The voice, with a southern accent, sounded scared and appeared to say a single word: "Mayday!"
Antonio Alvernaz said he was cutting scallops in the back of his boat when he heard the faint transmission over his radio. He ran to the wheel house, where it was quieter and where there was a better quality radio.
As he got there, he heard crew member Joe Neves speaking into the radio: "Come back with that! Come back with that more clearly!"
A radio transmission from another boat, came back: "I couldn't make out a ... thing he said."
Alvernaz then got on the radio and said, "It sounded like a mayday."
And then ... nothing.
"That was it," Alvernaz said. "Nobody got on the radio."
Alvernaz testified the weather was bad, with 35-knot winds and 10 to 12-foot seas.
The voice he heard on the radio "sounded very scared, frantic, barely audible, one quick `Mayday!' " he said.
He said he hoped the voice was a hoax, something that is loathed but not unheard of on the seas. He did not call the Coast Guard to report his concern because there were dozens of other boats in the area, and almost no one else indicated they had heard anything.
"You mention a mayday on that (radio) channel and the Coast Guard will jump all over it," he said. "In the future, I'll call the Coast Guard and tell them I heard a faint mayday."