This week Merrymaker Cruise lines has filed a $700 million lawsuit against Wambaugh Marine Industries, a shipyard that filed for bankruptcy last November before completing a three-ship contract for Merrymaker. The Suit contends that Merrymaker suffered $400 million in additional construction costs arid lost passenger bookings and also seeks $300 million in punitive damages. In 1987, Merrymaker signed the $600 million contract with Wambaugh for three 2,600 passenger ships, but the bankruptcy halted all work at the shipyard. The Suit also contends that the yard misrepresented its financial condition in order to get the Merrymaker contract.