How do you get a diving helmet in Dizzywood

You need to win it from fishing at Breakwater Beach. You need to get the fishing pole there first. If you have the Ghost Ray Power, use it on the broken boat in the water. Walk down from the entrance into the water as far as you can until you see the broken boat and then use ghost ray on it to get the pole. Then just keep fishing for a while and eventually you will win the diving helmet.