I am shocked so many of you don't think tips are being given. The average knowledgable (mostly US and Canadian) person pays by Credit Card and usually adds a tip of 20% of dive cost to the crew which is then split. Giving cash to all members of the crew is also acceptable but you must remember to stipulate it is for all members just in case captain is not honest. All crew potentially puts their life on the line for all guests so remember that when you are worried about parting with a few dollars. As for those diving in the Caribbean all dive staff are paid very low wages and are essentially working for their tips. Unfortunately most Europeans don't tip and the dive staff know this so you are not given the same quality of VIP service or the location of your dives might be sacrificed for a shorter lower quality dive site. Most dive staff will do their best to try and avoid having Europeans on their boat so if you want better treatment by the crews in the US and Caribbean you better start changing your reputation by tipping the expected MINIMUM 20% to be split by all the crew on your boat. In my view your lack of knowledge of what is expected is a convenient way of being cheap. If you can't afford to boat dive and include the tip you better consider shore diving and the risks associated with diving strange sites on your own. You get what you pay for.