I've got something simular... they are a lot of fun.
I wouldn't dare run it around real boats though, it is pretty squirrely, and it has a direct-drive prop shaft, and that means it does not stop! The only way to stop these things is to grab it out of the water as you idle it in, and then pinch the gas line, or run it out of gas.
The other downside is they take on a lot of water, and the batteries are always getting wet and going dead.
If you had a couple of these things to race against each other, you could spend all day at the lake and not even launch your real boat.
Mines the kyosho nitro .16: