I read the entire Airlock thread with great interest since I have experienced a catastrophic (by catastrophic I mean irreparable damage to camera or lens) flood myself. Mine, however, was caused by a user error that would not have been prevented by a vacuum system.
Can you please explain this ?
I was having problems with one of the controls on the Nauticam, and I opened the housing on the boat between dives to reseat the camera. Upon closing the housing, I missed a latch, and flooded it in the rinse tank.
The Vacuum system would have saved this. You would have never have been able to hold a vacuum. Yes I take my light weight (less than 1 lb) pump on the boat with me just in case.
True, but if I had just bothered to look for bubbles in the rinse tank it also would not have been the disaster it turned out to be. And that is the point of this thread. Not at all to discourage people from using a vacuum system, just to explore whether it actually saves cameras that would not have been saved by a dunk in a rinse tank.
And that leads me to this thread. I'm curious if the vacuum system reveals leaks significant enough to damage cameras, that would not be otherwise be detected by the old and faithful bubble check in a fresh water tank. I do realize that dunking in a tank does not put any appreciable pressure on the o-rings, but it will show you if you have a serous leak.
The answer to this is a yes if you let it sit long enough. Also it helps detect leaks from knobs and push buttons as it is hard to actuate all your knobs and buttons while doing a quick dip in the tank.
I would guess, and this is only a guess, that control leaks that develop during a trip would be far less likely to occur, and less likely to cause damage, than main housing and port o rings. Also, I assume a vacuum system cannot tell you where a small leak is occurring, so having that information would only mean reassembling the housing, testing again, and retiring the kit for the rest of the trip if there is still a slight leak. There is no real point here, I'm just thinking out loud about what you do with small leak information once you have it.
If you have a small leak, fill the housing with paper towels etc. and weights. pull a vacuum on the housing and submerge it for a while. release the vacuum, carefully remove the paper towels to see where they are wet, that is where you leak is.
Good thinking on that one. Are control leaks field repairable?
I'm trying to get an idea of the actual, rather than theoretical reduction of risk you achieve by adding the pressure system vs a careful examination of the housing in a rinse tank. After all, it costs $500 and it's yet more stuff to keep up with. $500 is cheap if it saves your camera, of course.
It's more than saving your camera, it saves the camera, lens, housing and dive trip. Lets face it no one is a happy camper after a camera flood.