Kirk, is that 45 000 or 45 00
We used scuba tanks, 3250 PSI to fill the round boat fenders, used as lift bags, for lifting cannons, and such, treasure diving on Spanish wreck sites. Had several for trying on logs, but, never had the open space in the narrow rivers, to use them, without boats running over them, if the log lifted overnight.
Airlift needs a decent depth of water, to get enough OOMPH to pull the sand and debris up the tube. The tube is only attached to the airline, which enters near the very bottom end of the tube, so the rushing-expanding air creates a suction as it rises. We had a 6" and an 8" when working the Bahamas wreck site. When a Conch shell goes up the 8" tube, and falls back, it hits the hard hat diving helmet, OR, hits a shoulder. It CAN hurt. Also, if you let the tube get away, it will start digging to China. It's hell getting the valve turned off, when trying to fight the lift, the weight of the tube, and sliding around in the loose sand you are breaking loose.
I LOVE working in the water. Keeps you thinking, so you don't get screwed up. That log diving was in coffee stained water. Couldn't see past your hand, or even not that far, sometimes.
I'm hoping to get a chance to visit the guys operation. Another chapter in my adventure novel.
With the current price of gold, when are you headed off to Haines
I could do a visit up there, also. I gots 'sperense gold getting, even dredging.