I hope that is made clear in advance and that you back off when a diver asks you not to do it. If so, there's no issue. It's when charters load your gear (Not necessary, but I don't have an issue with the crew loading my gear if they want) and then set up your gear without telling you that weas their plan that really ticks me off. Fortunately, that is extremely rare. When it has happened, I break it down and start from scratch.
If you ask the right questions, you will find out things like this when you make your reservation. Otherwise when you bring your gear bag to the boat ramp/dock you will see it happening and/or be informed of the procedure.
I'd like to point out that the crew very rarely does what they want; we do what the owner/operator requires us to do.
MY most recent employer loads guest gear while the boat is still on the trailer. The Guides duty at that time includes asking the guest to hand up reg and BC; our employer does not want us rummaging through strangers gear bags. As stated before, there have been a couple guests who refused when I was working. We handed down a tank so he could do it and then the Captain handed it back up.
We turn the air on to check fill/gauges/computers, then
we turn it off and purge lines. After guests board they are encoraged to check their gear, but if you leave the air on at that time
we will turn it off again; there is a 45 minute boat ride to the site and losing air underway is not a professional boat ride.
After the first dive you will be asked to sit at the rear of the boat and get out of your rig. A crew member (Captain or Guide)
will turn your air off, disconnect 1st stage and BC from tank, carry tank and gear to fresh tank/empty tank slot, put empty tank in and secure it, remove fresh tank and assemble your gear on it, check fill,
turn air off, purge lines.
At the end of the dive you again take a seat at the back of the boat and get out of your BC.
We turn your air off, disconnect 1st stage, dry and secure cap, remove BC from tank, dunk entire rig in rinse water and hand it to you to stow. On a typical trip the crew turns guest tank valves off a minimum of 4 times.
If we are asked by a guest not to do any of these duties we will
try to remember, but we are a pretty efficient team and things happen pretty fast.