Due to my work schedule I was unable to take the SSI dive classes at my local dive shop. They do offer private instruction, which I signed up for. My instructor has been great and I am down to my last 2 lessons. I realize with private instruction they do not make as much as when they teach a full class. I would like to tip him but do not know how much. I was thinking $100 or so. Any suggestions (esp if there are any instructors out there) would be greatly appreciated! Thank you in advance for the help.