The story opens with Sylvester rummaging through trash cans for food. When he doesn't find anything worth satisfying, he is very sad and goes to the dock. As he is sitting there, he is by a cruise boat and Tweety is swinging in his cage. When Sylvester sees Tweety, he calls Tweety his breakfast and Tweety slams the port door on Sylvester dropping him in the water.
Sylvester manages to come on board and decides to go into the cabin where Tweety is. Eventually, he gets Tweety in his hands and starts to go out only to find Granny there at the door very angry wanting to know what Sylvester is doing to her little bird. Sylvester laughs and gives Tweety back to Granny with Tweety replying "Ooh, what a hypotwit." A chase ensues with Granny hitting Sylvester with her umbrella. During the chase, Granny loses her glasses and can't find them. Sylvester sees them and kicks them under the couch. Another chase starts with Sylvester chasing Tweety around the cabin. Soon, Tweety finds Granny's glasses and climbs on her and puts the glasses back on her and then Sylvester jumps into Granny and then she misses hitting Sylvester eventually chasing him outside and throwing the umbrella at him.
The cruise ship sails off with Granny and Tweety saying "Goodbye" to everyone and Sylvester as a stowaway on a little boat with the number 13 on it.
Tweety and Granny are resting on the deck so Sylvester decides to do something about getting Tweety and paints a picture of Tweety on Granny's glasses. Sylvester opens Tweety's cage and then Tweety yells "Help" and then Granny is worried about Tweety and then she sees Tweety, unknowing that Sylvester had painted a picture of him on her glasses.
Sylvester chases Tweety onto a wire where Tweety goes across safely and Sylvester is having trouble coming across. Tweety springs the wire so that Sylvester is now with his paw hanging on the wire. With Sylvester sweating bullets, Tweety starts doing an "Eenie, Meanie, Minie, Moe" and when he goes to Moe, Sylvester falls and splashes into the water and Tweety replys "Well, what do you know, no Moe."
Rough seas eventually makes Sylvester seasick. When Tweety sees Sylvester all green, he laughs and offers Sylvester something for his tummy, a nice piece of salt pork. When Sylvester sees this, he turns different colors and becomes even sicker, going to the medical room to get some seasick remedy. Composed, he chases Tweety all over the boat, eventually going into the furnace where Sylvester yells and falls into the water.
Back on the boat, Sylvester sees Tweety, Tweety shows Sylvester a picture of a boat in the sea and he is moving it back and forth and Sylvester gets seasick once again. This time, Tweety makes it to the medical room first, with Sylvester running to the medical room very sick, and Tweety fills the seasick remedy bottle with nitroglycerin. When Sylvester drinks this, he starts spitting up sparks and another chase ensues with Sylvester spitting sparks at Tweety.
Granny is now upset that she has been tricked and gets stopped by Sylvester with a bunch of nitro in him and starts hitting at him. Tweety tells Granny to stop, but an explosion occurs and blows up Sylvester and Granny both, and Sylvester is up in the air and a flash blows up. While Sylvester is coming down, the captain says "I Thought I Saw A Putty Cat", and then when Sylvester comes down and falls on the captain, Tweety and Granny replies "You did, you did see a Putty cat." with Granny in a captain's suit and Tweety with a sailor's cap.