and seems to bear no relationship to the level of service provided.
(For those who don't know, I am a working dive instructor in the Caymans.)
Our boat usually goes out with 2 or 3 staff (captain included) for each trip. We load all the tanks, bring rental gear down, carry customer's gear from the dive shop down to the dock, set up weight belts, and assist divers in setting up their gear if they request help. We'll act as in-water guides, and help in any way we reasonably can with other dive related activities.
Tips vary widely from a low of zero to an all-time high of over $400USD per staff on a morning two-tank dive. (Many more zero days than $50 days) Some tips have also included beer, booze, gift certificates, and even a gold coin. Those who do tip usually leave $10 to $20 to be shared amongst the crew for a two tank dive. But since only a portion of divers do tip, each staff member averages $20- $25 each two tank dive.
Oddly enough, from a tipping perspective the words I most cringe to hear are, "That was my best dive ever." While I do appreciate the feedback and am thrilled that you enjoyed the dive experience, for some reason I hear those words on days when the tip total is zero.
If you want to provide a tip that will be truly memorable, take the time to write a note of thanks at the end of your dive week. Be sure that your praise (or criticism) is also sent along to the dive shop manager, and/or the training agency.