Interesting.
I've been under boats a number of times for repairs, etc. It's a bit more challenging to do it without a tank......
I'm using a hookah in the video. I would consider it unprofessional to do this work without surface supplied air. Or to do it while wearing a tank.
Yes. I consider it unprofessional to wear a tank under a boat. Too much potential for damage to occur. Tanks should be left topside and used with a long hose, IMHO. This is known as a "SNUBA" rig.
If you bond your shafts using shaft brushes, shaft anodes can be eliminated. I made my own shaft brushes which work well. I verify my single (stern mounted aluminum diver's plate) anode's performance using my silver-silver chloride half cell.
Wow, now THAT is an angle I have never thought of when it comes to diving. hmmm
Yes. I consider it unprofessional to wear a tank under a boat. Too much potential for damage to occur. Tanks should be left topside and used with a long hose, IMHO. This is known as a "SNUBA" rig.
Most shafts are bonded with or without brushes.
How do you place jumpers onto a rotating shaft? I can think of only one exception and that requires a thrust bearing.
What sort of damage? Other than convenience, I wouldn't have thought the two approaches to be any different.
We added a jumper on ours. Using 2 ring lugs that fit the coupler bolts and ~3" of #10 wire. We jumper across the coupler on the same bolt. Our shaft is 2" diameter that spins at ~800-900 rpms. The shaft runs true and the alignment is good.
Like this........ from Nigel Calder's book.....
For my brush, I use a discarded out drive zinc...already has a bolt for the bonding wire and arm attached. Got 3 seasons from the last and free from the marina pile is hard to beat.
As OC mentioned, it is very easy to imagine a diver with a bulky tank on his back banging up a boat's anti fouling paint or even gouging the gel coat.
From a personal standpoint, when I see a hull cleaner in the water or on the dock with a tank on his back (which is not often), I assume he doesn't know what he's doing. In any event, I do not allow my divers to operate that way.
BTW: I do this while at anchor and not while at dock for fear of stray AC currents that might kill.
I often wonder if bottom cleaners who work around docks ever run into too severe AC currents in water???