The return skipper told us we had run the generator for less than 12 hours during the entire trip. "Everybody's different. Just the other day I had someone return the boat with 125 hours of generator time for a week --- he had to refuel the boat mid-week!" We would later learn that we'd only run up $95 in fuel, a testament to how little we ran the engine and generator. They charged us $33 for the boat hook, which we had known about, but otherwise everything was fine.
Once ashore, a taxi took everyone except Arturo and I back to the ferry terminal, where we bought tickets for the return to US waters. (We opted to walk to save the $5/person cab fare) Once in St. Thomas, U.S. customs gave the green card holders a long wait while the US passport holders had no trouble, but we weren't in danger of missing the flight.
At the airport, Arturo kindly took our check-in baggage because his generous baggage allowance would let him took it for free. Bowen told me we were coming back again next year, while Xiaoqin said she wished we'd done more diving.