Thanks to the Hawaii Gay Flag Football League (HIGFFL) for providing this Info

Snorkeling

Snorkel Bob's is an inter-island outfit that provides snorkel equipment rentals. Located about a 5 minute drive from the host hotel. Friendly staff and affordable rates and you can reserve equipment online. They provide maps and recommendations for the best snorkeling spots on the island (hint: the best snorkeling is done in the early daylight hours). Visit their website.

Surfing

Big Wave Dave Surf School helps you turn your surfing dream into a reality. The feeling of a ride lasts a lifetime and is one of the top ten things to do on during your Hawaiian vacation. Dave offers group lesson and individual lessons. Visit his website.

Waikiki Surfboard Rentals is located one block off of Waikiki Beach. They'll outfit you with a surfboard, a paddleboard and you can even rent a GoPro camera at this shop.  Visit their website.

Sailing

Tom Barefoot's Tours include sunset cruise packages on Waikiki. These cruises are  usually just a couple hours in length and occur during the most beautiful two hours of the day. This is a time of the day to unwind and relax with a cocktail in hand and share in the day's adventures. Visit their website.

Scuba

Waikiki Dive Center is located 3 blocks from the host hotel at XX Nahua Street. They offer diving certification, diving tours and fishing tours. Their staff are also some of the most friendly people in Oahu. Visit their website.

Living Ocean Scuba offers scuba diving at Hanauma Bay for both certified and first time divers. They provide a free shuttle from Waikiki to Hanauma Bay. Visit their website.