Grey 2112, you presume wrongly in answering your question. A properly drawn release can offer protection from liability. However, if you as the boat operator know that there will be scuba diving on your boat, you still are required to act as a reasonable person would under the circumstances. That would likely include having )2 on board and knowing haw to administer it; having a safety plan with ready telephone access to emergency medical services, Coast Guard, and the nearest deco chamber. You do not need to have the credentials you list, but if you did, then your standard of care will be higher. Also, it will make a difference as far as responsibility and liability if people are paying you for the excursion as opposed to taking a few friends out to the reef for fun. You should also read your insurance policy concerning what is covered and what is excluded. Everyday thousands, maybe tens of thousands, of boats take people diving without anxiety, because they have engaged legal counsel to prepare proper forms, have formed an appropriate emergency plan, and follow it. I caution you to not trya and get answers to important legal questions from unqualified people. I have practice law for 35 years, and still do. What I have shared here is not enough to answer your question. If you are going to run a dive boat, volunteer or otherwise, spend a little money preparing to do so from a legal perspective, paying your own lawyer, who you want to be sure is himself insured, so that any issue can fall back on the lawyer if they steer your wrong.
DivemasterDennis