Dookie is correct, the Mamba 8000 is way too much motor for almost any direct drive boat. On 6 cells the motor would run at over 48,000 rpm to avoid overheating, that is world record speed competition running for just a few seconds at a time, and in a rigger, not a "wave jumper". The 8000 motor must be used with a gear drive on 6 cells, period. Too, it is smaller than the typical 05 car motor and would be more heat sensitive in a boat. Bottom line - bad idea.

But you already have the MAMBA 8000, so what to do with it? Run a 4 cell pack and a small prop. In a small boat. You might try a Hobico Reef Racer, it will handle lots of waves, will give decent speed, and is close to your price point. I do not know if the factory prop is too big or too small for the Mamab 8000 however. Remember, FOUR CELLS! And tape the boat up good to keep out water!!!