If you were looking to get paid and he wasn't ponying up I would have cut my losses and stop taking him before it got too out of hand. After two trips of nothing I would have cut the guy loose...when he calls to find out why just be honest...fishing is expensive and you have a few people who help you cover the costs. If he wants to fish again he'll do the same! As far as "more than half" this is actually reasonable in my opinion but not easy to enforce. After all, you pay the insurance, tune-ups, new tires etc etc for the boat/trailer...its just hard to ask for more than half. Usually I go half half with people, but then let them buy me a coffee and bagel when we stop. The odd coffee/bagel is nowhere near my cost for operating the boat and keeping it on the road, but its better than nothing