Thanks to everyone.
Turneffe Island Lodge has a sheet with a suggested range of tips for the entire island staff from the dive masters and boat captains to the landscape crew. You can pay in cash or put it on your credit card tab (or be a jerk and pay nothing at all, I suppose). Makes it easy.
I was wondering more along the lines of the three tours I'll be taking when we get to Belize, all arranged through TIL.
For example, I did the Zoo tour two years ago. TIL made the arrangements, and I paid by putting it on my tab on the island. Cost was something like $100.
A guide picked me up at the dock at 9 am. At my request we swung by his house to pick up his little boy, then drove the 30 miles or so to the Zoo. We toured the Zoo together, talking about the animals. I bought lunch for the three of us at a roadside stand in Hattieville. We were back at the dock around 2 o'clock.
I had no idea what to tip the guy. Obviously, he was paid to be my guide, but I assume TIL got a cut for making the arrangements and I don't think they dealt with my guide directly so there was probably a middleman as well. In other words, two other entities took a bite out of that $100 apple.
Under the circumstances, tipping him 10% of the cost of the tour, i.e., $10, seemed too low. My impression from my short time in Belize City was $10 wouldn't go very far. I think I tipped him $40 or $50 plus gave the kid a small tip, too (he was thrilled).
To paraphrase Goldilocks, was that too much, too little or just right?
On the day of our departure, my wife and I along with another couple did a tour of Altun Ha. Again, TIL made the arrangements, and I assume went through the same middleman. A different guide picked us up. After doing a quick tour of Belize City at my request, including a stop off at St John's Cathedral, we spent several hours at the ruins before heading in to the airport. Again, the guide showed us around, explaining the history and so forth. I can't remember the cost but let's say it was $150.
When we were dropped off at the airport, I tipped the guy around $50 or $60. The other couple didn't tip him at all, which I found surprising.
Again, too much? Too little? Just right?
And while I'm asking, what's cab fare from the airport to the Ft George area? Two passengers, dive luggage and carry-ons.