just some suggestions from the point of a gamer;

-The start is pretty linear, even though its probably not true of RC boats, you should have a revving and an art to the launch (not revving until it hits green or your boat goes slow?)

-Also you need to have some choice, secret passages or mulitple ways to go (one way could be quicker, but is harder to navigate).

-The snakes were a nice touch, but I found I often got tangled with them and was stuck for a huge amount of time, maybe if they sank once you hit them? Or if they sped away quickly once you hit them (so it wouldnt be as frustrating)

- The turns are good but it should be a little harder to make them, so people would have to slow down a little to pull a good turn, and drifting would be nice once again, but i dont know how hard that is to do.

- Past that you could have damage models, so if you hit a wall/animal/another boat X times it the boat either sinks or explodes (differant models replace the boat as it gets more damaged)

Just thought I'd add my 2c on what could make this game addicting and fun