Northwest Dive Club

Hello All,

I have been put of the water for a couple of years and have only done about six dives in the puger sound.
I am an average but heavy body type in water at 185lbs and 5' 10"
I am diving a doubled up farmer john style wet suite at 6 mil and 7mil everything else.

I am asking if anyone can give me a good absolute minimum weight I would need so I can prepurchase some pocket weights for my BCD. I am offshore in Trinidad and bored sailors with a connection tend to land on dive gear sites.

Mike

An "abosolute minimum" is a tough number to throw a guess at without knowing all the variables.

- What tank(s) will you be using? Aluminum & steel have significantly different buoyancy characteristics.
- What type of BCD? Is it negative or positively buoyant - and by how much?
- Are your fins floaty or heavy?
- What other gear are you carrying that might affect buoyancy? Pony tank? Camera?

Considering your time away from diving, and limited experience in cold water, I'd expect you to need at least 30lbs of weight, probably more. Having a few extra pounds of weight available to dial in to your exact weighting needs would be a good plan. My recommendation would be to obtain at least 36lbs of weight, in various sizes (between 1-5lbs), so as to provide you the most flexibility. A good combination would be 4 x 5lbs, 2 x 3lbs, 4 x 2lbs and 2 x 1lbs.

I would have to agree with 35# or so, this way you have some buffer for different tanks. If you use an aluminum and then go to a steel, this will be a substantial weight change. In my drysuit (much more buoyant than wetsuit) I wear 20# with backplate and steel 120 when diving singles.

Back in the day when I was assisting with students our rule of thumb was 10% of your body weight plus 10 pounds to start and then once we got them to open water we would add or subtract as needed.

They were using double layer (farmer john plus top) wetsuits and aluminum 80 tanks. We wanted them to be heavy at the start of the dive so that they would be close to neutral towards the end.

Mike

yup, agree with ballpark 35 to start, probably drop down to somewhere between 30-33lbs with a jacket BCD and Aluminum tank, depending on your body composition. You'll be heavy at start of dive but as Mike says, the buoyancy shift from slurping down a tank needs to be taken into account.

Personally I do not take into account heavy camera or other non-attached gear because I don't want to fight my buoyancy if i set it on the bottom or have to drop it in case of emergency and have zero gas to dump, on the flip side if my camera is floaty, I trim weight the camera to get it as close to neutral as possible as opposed to adding weight to myself.

As mpenders states, DO take into account 'fixed' kit like canister lights, weighted single tank adaptor (STA), pony bottle, etc, but it sounds like OP is still a little ways away from worrying about that.

I probably should have clarified my concerns with camera, pony tank, camera and the like.

You can't determine your absolute minimum weighting while carrying items that might be accidentally dropped, intentionally ditched (excluding weights) or emptied.

Ultimately, you still have to be able to hold a safety stop after emptying your main tank, dropping your possibly negatively weighted camera and breathing down your pony tank (or having the empty and now buoyant pony tank strapped to you while you're breathing off your buddy's alternate).

Thanks a bunch for the input! I am on a oceanic, back horseshoe style BC negative about a pound. I will be using Al 80s to start. Fully plan on a refresher and advanced to get my night and nitrox card. No cameras to speak of, but I am considering a separate pony as backup as I have another good regulator with a good secondary (better than my octo for flow if buddy is in a panic).

Any recommendations on a pony would be appreciated. I do not plan on dives deeper than 120 and I would like to dive it with air and be able to switch it to Nitrox, is this something that can be done? I don't want to spend the money just to replace it after I get nitrox-c.

I am purchasing two integrated ten pound weights. two four pounds, two three pounds, two two pounds, and two one pounds. That should give me a wide range and have some spares in case someone is short before a dive. I can keep then with my save-a-dive kit.

PS: should be diving Tabago on Sat/Sun.... Yay!

The general rule of thumb here is not dive deeper than the cf of your tank. Keeping enough reserve gas for you and a buddy to get to the surface in an AL80 is a challenge below about (wait for it...) 80ft!

There are a bunch of local instructors offering free evening seminars on gas management. You might look it one once you arrive.

I would avoid Aluminum tanks if you can help it. They are about 4 lbs positive with 500psi left. That's 4 extra pounds you'll have to carry in your BC or on your belt to make up for it. Different tanks have different buoyancy characteristics. I was able to drop 6 lbs when I bought my tank because it's quite negative compared to a standard LP steel 80. I'm down to 20ish lbs now.