Dick gets the sack and Duncan resigns in protest. With Collier gone and the Binghams bringing up triplets they've nothing to stay around for and become ship's doctors on passenger liner the Begonia, only to find the captain is Sir Geoffrey's twin brother Norman. Next day they are shipped aboard by a crane to a very dirty ship whose last doctor died of suspected parrot fever and where they are likely to be pursued by crewman Mad Jake. Fortunately they find out in time they're on the wrong ship, it's not the Begonia after all.

Having put to sea, Duncan discovers that he is prone to sea-sickness so Dick gives him a healthy dose of remedial medicine. Unfortunately he overdoes the dosage and Duncan falls into the ship's swimming pool, arriving soaking wet at the captain's cocktail party. The captain sacks him and in revenge Duncan tells American passenger Mrs. Tranmere that Loftus loves to sing, so she asks him. Ultimately Loftus reinstates Duncan because the party was a huge success, due to his singing.

There is a loss of manpower on the Begonia because Dick has been doling out sick notes or chitties to the crew. Captain Loftus discovers this and threatens to sack him. Industrial action is called. However, when the ship arrives in Madeira nobody wants a chittie, as it would mean missing shore leave. Dick has been fooled by the crew. He has, however, made money by selling the chitties at two pounds a time.