"...was a quiz called "Double or Drop", where each contestant was given a prize to hold for each question answered correctly, but given a cabbage if they answered incorrectly. They were out of the game if they dropped any of the items they were holding or received a third cabbage..."
Thi is a bit of a misleading question on the part of the setter as Ted Heath had 5 boats called Morning cloud. I think you'll find 3 of them sank but certainly by no means all.