Atlantis Submarines
- Underwater tours from Kailua pier to coral reefs and underwater ecosystems. Small map and online reservations available.
- http://www.atlantisadventures.com/kona.cfm

Trekking Hawaii: Sea Kayaking on the Big Island
- Established by Kelly Harrison in early 2002. Includes guided day and overnight trips, hiking, snorkel tours, company philosophy, terms and conditions, rates and forms of payment accepted.
- http://ourworld.cs.com/trekkinghawaii/