I certainly wish I'd recieved this advice from scubaboard when I asked the same question, so many years ago. 

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mattsI am very, very opinionated about this….my flame suit is on too. I am American and waited tables and bartended for many, many years. One can safely say I am a big tipper. In the US I always tip at least 20 percent/a dollar a drink..
Massages a nicety and greeting great fun but were those things worth a change in tip from IDR equivalent of $10-20/day to $60+? (As 10% of lob cost at the time, ergo tip of $600 USD) that was very painful for me at the time as a Canadian, lol
Thanks for all the replies! We will be on the Blue Manta Oct 20th to Oct 30th 2018 in Raja Ampat. Yes, there are cheaper boats but it is our anniversary and we liked what we read. Imho we are paying top dollar and kinda expect a trip that will blow our socks off. Where we booked thru they 'suggest" 10% to 20%, that was not going to happen! We will tip but not to the extent of their advice. We really hope this will be a trip dreams are made ofBill and Dee Dee
I also suggest taking Pepto Bismol 4x/day as a preventative. Anyone can get the runs when going to a new area -- it doesn't mean bad water or bad food, just new bacteria. Good insurance on a trip you've invested a lot in!
- Bill
That says more about the dive OP manager than his guides or the people tipping the guides.Last year a dive OP manager told me that he wanted the tips to come to the office, even if with an extra envelope for the guide, because he was determined to ensure that none of the guides were abusing the flora/fauna in an effort to assist photogs to get an extraordinary photo that they wouldn't otherwise have been able to capture, had the guide not mangled/moved coverage and harassed the elusive creature out into the open. He sent on to tell me that he could easily tell which guide needed enhanced instruction on reef preservation because if Larry and Moe regularly made an extra $20 but Curly more often made an extra $100, well . . .it was apparent what was going on.