Buoyancy

I have been using fishing sinkers to make small modifications to the buoyancy of my rig, during the dive.

It seems to be a trial and error process, because what works in the dunk tank doesn't necessarily transfer to the deep.

Is there any golden rules to mastering buoyancy?

Rigs are pretty subjective due to preferences and style of shooting.

Most people want a negative neutral (100-200g) with balance that allows the housing to stay horizontal without any pitch or yaw torsion. The center of gravity should be low and central so if you point the camera up or down it doesn't fight you. This is optimal for WA water column shots.

Of course if I were shooting macro on black sand, I'd want it more negative so I can set it down on the sand.

I like my housing as close to neutral as possible. I find it helps keep things steady. I also use little 4 and 8 oz fishing/trolling sinkers.

When I want to set it down in the sand or use the tripod, I put an 2-3 lb softweight on top of the housing.

I also always put a emergency release weight (4-500g) on the housing if ever I have to let it go, at least it'll float up and become a shipping hazard if not recovered.

Of course, don't do it if you're not going up with it. Otherwise you set the boat on panic mode cos you still haven't come up. (Sorry Wade )

I also use little 4 and 8 oz fishing/trolling sinkers.

I am finding the sinkers really handy as I move things around on my rig. Glad to know I'm not the only diver stocking up on fishing sinkers. The guy at the tackle shop wondered "what fish I was going to catch?"

Yeah, the trolling sinkers are shaped just right and the loops at the ends plus 2 reusable zipties makes it easy to get the buoyancy the way I like it.

My new setup was naturally negative by around 350g which I found it a bit too much whilst on the first trip with it. Didn't have any floats so I went into KMart and bought one of those tube float things that kids hang around on on the pool. A short length of that slipped over the strobe arms sorted it nicely.

You might say, that stuff crushes under pressure, and yes it does but the side effect of this is that it now floats on the surface, very secure feeling when its handed down from the boat. By the time I'm at 4-5m its neutral and at 30m weighs maybe 200g. All quite manageable.

Balrog

Divinyl Cell doesn't crush but is made of PVC. Works great on my heavy housings.

Balrog

Divinyl Cell doesn't crush but is made of PVC. Works great on my heavy housings.

I read many of comments on adding floatation to housing rigs. Is this the preference? I am finding that I need to add weight, not add buoyancy.