In November 1973, a 56-foot Chris Craft cabin cruiser named Sea Boy II left Washington for the sunwarmed beaches of Nassau.

One month later, searchers found its broken remains, apparently sunk at anchor, on the sea bottom near Holmes Cay in the Bahamas. No trace of its eight passengers was ever found.

Whatever happened to the boat -- and the theories range from storms to piracy -- its designers and owner's insurance company this week agreed to pay a total of $790,000 to the victims' survivors to settle lawsuits growing out of a voyage still shrouded in mystery six years later.

Aboard the Sea Boy II in December 1973, were three Washington area residents and a family of five from Virginia Beach. All were related to the boat's owner, Eleanor Baldwin of Upper Marlboro, whose insurance company has agreed to pay $775,000 of the claim.

The other $15,000 will be paid by Chris Craft Industries Inc., the designer of the boat. The firm has steadfastly denied any design flaws in the 1956 boat, but decided to pay that amount solely to end the lengthy and complex litigation, according to court records.

Also sued in the round of legal maneuvering after the boat sank was the U.S. Coast Guard, whose rescue efforts were questioned.

However, U.S. District Senior Judge Howard F. Corcoran ruled earlier this month that the Coast Guard did all that it could have or should have to find the boat.

"Simply stated," Judge Corcoran said earlier this month in ruling in the Coast Guard's favor, "the loss of the Sea Boy remains shrouded in mystery."

He said "violent weather, inexpert seamanship, poor structural maintenance and other more exotic theories" about the boat's disappearance in the Bermuda Triangle had been advanced during the litigation.

"The extent to which each may indeed have contributed to Sea Boy's end will never be known," Corcoran added.

Michael Baldwin, 28, of 9540 Muirkirk Rd., Laurel, the nephew of the boat's owner, was at the wheel of the vessel on the cruise out of Washington. Also aboard were Richard and Nancy Mazzullo of Virginia Beach, their children, aged 10, 7 and 2, and Thomas and Kathy Mazzullo of 5012 60th Ave., Hyattsville.

Thomas and Kathy Mazzullo's two surviving children, Suzanne and Deborah, are the main recipients of the settlement, which is so complex it takes three legalsized pages to list its details in court records. Attorneys who handled the cases for the estates of the victims are scheduled to receive about $189,000 of the settlement, according to those lists.

The Sea Boy was cruising through the Bahamas and had left Freeport on Dec. 19. The next day, 12 radio transmissions purporting to be from the boat were monitored in the area during the day.

At 8:05 that night, a Yugoslavian tanker received two garbled "Mayday" (emergency) calls from a vessel identifying itself as the Sea Boy, and gave a location near Whale Cay.

The "Maydays" were widely rebroadcast, but there are two Whale Cays in the area, and since no further contact could be made, no search was begun. There were also storms reported in the area, the court found.

Early the next day, while responding to a "Mayday" call from another boat, the Coast Guard began a partial search for the Sea Boy. It resumed the search later that day after the vessel was officially reported overdue at Nassau. Its remains were discovered at 11:20 a.m. on Dec. 24, 1973.

"Why the Sea Boy II sank on or about the evening of Dec. 20, 1973, is unknown," attorneys for Chris Craft said. "Whether or not the decendents were on board her when she sank is pure conjecture." Chris Craft's attorneys argued that the ship was probably at anchor, and "caught in a severe gale" when it went down in the ocean. They also surmised that the vessel could have run out of fuel and its occupants perished in a life raft after leaving the ship.

"Finally, a collision between the Sea Boy II and another vessel, or floating debris, or a coral shoal, must be considered a possibility, as well as perhaps even the possibility of piracy's," Chris Craft's attorneys continued.

No trace has ever been found of any of the eight persons on board or of the life raft which was on board the yacht, or of the life jackets (40, in number) which were aboard the Sea Boy II," Chris Craft attorneys said.