1. If all the crew does is take you to your site, make sure you safely get in and out of the water - they're doing their job and exactly what I'm paying for. I don't tip.
2. If the crew meets my needs, gets the gear on/off the boat, helps me setup my gear, provides great briefings and information about the dive to make it more enjoyable - it's worth $5 per tank. They're providing additional services that help me enjoy the dive more.
3. If the crew does #2, provides in-water tours, has snacks/water/juices available, interacts with us to make it more fun, rinses my gear after the dives - basically pampers me, it's worth at least $10 per tank. And I tip even more if they really customize what they do for me and do it for every diver.
If you ever get a chance to dive here in NJ, I recommend the Stingray, Independence, Sea Lion, Spring Tide, Blue Fathoms, Lady Go-Diver, Depth Charge, or pretty much any boat but the Gypsy Blood.
