I teach CEC courses in aquatic exercise. They are for group or private instruction and encompass a very broad range of water exercises and options. It sounds like coming to the Big Island is not an option though. While aquatic exercise has a few differences to land based exercise, most are actually helpful to the performance of the exercises in terms of support, balance, and stability. Unless an “aquatic” certification is required by the facility, most fitness instructors can develop water exercise programs themselves. If you are not good in the water already, that could be an obstacle though. If you are at home in the water, I recommend that you experiment with movements and exercises to gain a better understanding of the aquatic medium. I do recommend that you either obtain a lifeguarding certification or instruct at facilities with a lifeguard present. It is always best to be safe. I used to teach lifeguarding and have been instructing clients from 94 year old post rehab to elite athletes in aquatic exercise for over 35 years. If you would like to check out my website, go to www.hawaiifitnessacademy.com . You can contact me if you would like any further advice or guidance.