Cabron said..
Not sure it's a great idea. Presuming you get a petrol version, there will always be fumes from the unit even if exhaust is outside, and inside your boat....not good....If i need to explain, this hasn't been thought through, and Darwin award winner is......
The units also get very hot, both motor and compressor.....and even bottle for that matter. The overheating of the motor would be my concern, I used to put the bottle in the water to get more air inside.
You also need good access at compressor to drain off the condensation from the compressor. There are many reasons why not too on a small boat, and not many reasons to put one in a small boat, how much diving do you want to do? Take a few bottles, or plan on having the compressor on deck to use, with lots of vibration, fumes, noise, and filling generally takes 20-25 min per bottle.
As a solution, what about a Hookah dive system????
We are experienced divers and we try to dive everyday. Taking tanks are just not practical if we want to go out for a week at a time, 2 dives a day for 2 people, our boat will be filled with tanks

. Hookah is out also, it's too restrictive, it's won't suit our diving style. Hopefully we can come up with a suitable dive compressor setup.