To answer the questions about the scuba class, most all of the technical diving classes such as deep diving, drift, nitrox, and shipwreck are both in class learning and then in water demonstration of proficiency. Also, from what i understand, padi and other scuba certification agencies have yearly due in the thousands of dollars plus any insurance coverage you might need. If you are still interested in becoming a scuba instructor I have a friend who is an independent instructor who might be willing to teach you on your boat. If your interested pm, and good luck with the business.