Hi all,
I must preface this reply by saying that I don't think there is a "right" way of handling a camera during entry or dive. Although the official reply is that the camera should be handed down once you are in the water, this isn't always possible or desireable. For example, if you are diving in current, you may not be able to get back to the boat after entry, as the current takes you away. So, you need to be prepared to vary your technique to suit the diving conditions. The reason, as I understand, for the "hand down" is to limit the shock wave caused by the camera hitting the water. The way I tend to counter this when I enter with the camera in my hand is to fully inflate my BCD, and fin hard once my feet are in the water- and hold the camera above my head. This means that the camera doesn't actually hit the water at all! I am shooting a PS camera, but I do have dual strobes and arms-and it seems to work. I have no experience of using an SLR though.
Further, I pre assemble my camera/housing etc on shore, and try to pressure test it by leaving it a bath or similar before I leave the hotel-in my experience, if it is going to leak, it tends to leak straight away!
Rinse tanks are as someone said above a nightmare-if am staying on the boat between dives, I'll dry the housing with a towel, and change cards/batteries. I'll then reassemble it and test the housing again-ideally by dangling it over the side of the boat etc! Then I'll try and keep the camera wet (with seawater). As long as the salt doesn't dry and chrystallize, there should be no problem with this. Obviously once back on land, a thorough rinse in fresh water is neccessary.
I tend not to use leashes underwater, and hold the camera in my hand-I have seen lots of lost cameras where someone has assumed the camera is clipped to them and let go-only to find it's not! Worst of all seem to wrist lanyards-these come off wrists for a pastime!
If I do need to clip the camera off (to deploy a buoy or whatever) I have a few small loops of bugee cord on the camera base, to which I can clip a double ended clip and then clip this to a d ring on my BCD. If I am hanging about for a while and need both hands, I'll use a spool (reel)-let a small bit of line out, and tie/clip one end to the bungee loop and then the clipped off spool to a d ring-this allows the camera to dangle below me out of the way. Thats normally when the white tips arrive, and I wish I had the camera in my hand!
These are just thoughts and ideas-the trick is to be prepared to change/modify according to the situation. As soon as anyone tells you that one way works in al situations, you will almost guarantee to find one in which it doesn't! Many years ago, an friend told me the adges that "the sea always wins"-and he was in my expeince dead right!
Hope it helps
Best
Adam