Ha! Not to laugh, but I can totally relate to not being near a bathroom. It's a hassle sometimes! On Kauai, we used Skyline Eco Adventures. They were just awesome with our son with special needs. I didn't think he could to it, they made it happen. We've also done the tubing on Kauai and it was great. Highly recommend it. The Kona-side of the island has some of the best snorkeling in Hawaii, if you're into that. The Bodyglove cruise leaves right from the pier (and has bathrooms) or you can take a cab or HOHO shuttle to Kahaluu Beach Park and rent gear (bathrooms at the beach). Lots of people fish off the end of the pier but I'm not sure where to rent gear. The beach right there at the hotel is great as well, with some amenities. My son loves to swim there. Kona brewing is only a 10 minute or so walk although you can get Fire Rock at just about any of the bars/restaurants on Alii if you decide not to walk. Our favorite is Chillin' on the Bay. Awesome bartenders, great view and always a mix of locals and tourists. They only have bottled beer, if that matters.