I just don't see how a small oilless compressor, especially a gas driven one is going to give you good air...unattended...I too have seen the local guys use some claptrap, rube goldberg device to dive, but then they all break every common sense dive rule known in doing so...
always dive with a buddy
know your gear
plan your dive, dive your plan
be prepared, crap happens
Never have I seen a "helper/watcher/buddy" on deck to plug the unit back in, or refuel/restart when it runs out. Or prepared to help him out. Add in the pollution, shock hazard, barnacle infections...
Actually one guy near me just lugs all his "dive gear" in a wheelbarrow, bangs out the last day's goop from his regulator, dons his wet suit and plunges in. Then gets out, plugs in the compressor, unkinks the hose, and tries again.
Yes he is still alive,
I have said enough, you guys just do what you want to...