This is a 1967 Magnum Marine 42' The hull was built by Don Aronow, who was also behind Cigarette, Donzi, and Formula. As you can see it is a salvaged boat. It was just removed from the water because it can no longer be stored at its current location. This vessel has had the motors removed but has not recently been underwater. It is currently located on land in Fort Lauderdale.
Here is a link to a project done on the same boat.
http://magnummarine.com/tj-kaltenbach-and-a-1968-magnum-marine-35/