You don't need a boat. Just take the bus to Hanauma Bay.

second that on Hauauma Bay BUT go early as it gets crowded and do remember that you will have to go thru the mandatory video on safety, etc., ....I have also used a tour company which included all the equipment..they pick you up at your hotel..not too expensive but only drawback, you are on their schedule which doesn't give you all that much time considering the lost time at the mandatory video. I generally take my snokel but not fins as they take up too much room. You can use snorkel Bobs forrenting those as well. The bus can be a bit slow, depending on the day. Once I waited over an hour and gave up....

The bus is simple and cheap, but you can take a cab, if time is important. It will still be less than buying four tickets with a tour company. Rent your equipment in advance or you can rent it at the bay. If any of you wear glasses, remember to ask for a mask with corrective lenses. They are wonderful!

Fun activities in Waikiki include the catamaran rides from the Hilton, and surfing lessons down by the Duke Kahanumoku statuer.

PS- you snorkel ON Oahu (an island), but do things IN Waikiki or Honolulu (a neighborhood and a city).
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