Question about dialing my weight in.

[purbeast]

I'm going to be using my own full setup for the first time this weekend down in the Keys.

It's a BP/W setup and I've tested it out completely in the pool, wetsuit included. Even with my wetsuit on and around 500psi left in the tank, I'm still negatively buoyant without any weight. I have to put like 4-6 small squirts in order to get neutrally buoyant when I had 500psi left in the pool.

When I go into the salt water for the first time this weekend, I plan on telling the dive master on the boat about my situation. I have 2 trim weight pockets that I plan to use if weight is needed that will be on my cam bands. I will also have my weight belt just in case, but I'm guessing I won't need it.

My question to you all is, based on the information I provided about my buoyancy in freshwater, what would be a good starting point for the trim weight on my first dive? Should I first get in the water with no weight to see if I need any at all? Or should I put like 2lb weights in each pocket and assume I will be a little overweight, and dial it in from there on the next dive?

Again I'm going to bring this up to the dive master that goes in with me but I figured it would be good to go in with a little bit of an idea about what to expect.

FWIW when I used rental jacket style BCD's prior to this, 6lbs of lead was pretty much perfect for me. My BP is a 6lb steel plate so I assumed that basically offset that weight maybe?

 

[Ben_3]

I think verifying your weights with the Divemaster is a must if you are unsure. Seeing you are negative in the pool even with your tank low on air, I would try the exact same set up for the first dive in salt water. Do a proper weight check though before the dive and adjust accordingly.

 

[DeepSeaExplorer]

I have a 6lbs plate and dive with zero additional weight. I would go with your plan to put one 2lbs weight in each pocket. It’s always better to be s little heavy. If that goes well on the first dive, you can probably pull one or both of them on the second dive.

 

[rongoodman]

You don't really give us enough to go on. What kind of tank? What thickness suit? SS or aluminum plate. FWIW, I use a SS plate, 3mm suit, with 5 lb additional in warm salt water with a rental aluminum tank. You can easily reach around and feel the bottom of your wing at your safety stop when you're flat or a little head down. If there's more than a fistful or so of air down there, shed a little weight before the next dive.

 

[purbeast]

I'm assuming it's going to be an AL80 since it's going to be in warm water and it's a 3mm full body suit.

And I did say it was a 6lb SS plate that I'm using.

 

[Neilwood]

Bearing in mind you are slightly negative at the moment but are going to dive in seawater (which will add buoyancy) and also dive an AL tank (generally more buoyant than similar capacity steel), I would reckon you will probably need to add some weight compared to the pool.

I would definitely do a weight check with it in salt water. I would tend to err towards being negatively buoyant (by 2-4lbs is not a huge issue) as it is a lot easier to add a skoosh or two or air when you are too heavy. If you are too positive, you have to look at harder alternatives such as having to actively fin down or take short breaths to minimise the effect of your lung volume.

I would always prefer to have to manage a slightly larger air pocket in the wing than actively having to try to keep myself down.

 

[purbeast]

FWIW, I was using an AL80 in the pool so the only thing that is going to be different (or should be different at least) is that it will be saltwater and it's different buoyancy properties.

 

[loosenit2]

The specific rule of thumb is to take your weight + weight of gear + weight of your tank empty, multiply this number by .025; that is the amount of weight you need to add to go from freshwater to salt water.

When I am diving a skin, no wetsuit I add 4 lbs going from 4lbs fresh to 8 lbs salt.

From there you can subtract a little weight until you dial in perfectly for yourself.

 

[Kimela]

I know this isn't always possible - heck, it's rarely possible - but if you can find a place to get in the water before the dive to do a weight check that would be ideal. We tend to 'go with the flow' when we're holding up a boat full of divers who want to go to depth. At best, make sure there's someone in the water with some extra weight for you in case you need it. Who are you diving with? Will there be a DM in the water with you? If, for instance, you're diving with Rainbow Reef, they'll have guides in the water who you can ask to carry some extra weight in case you need it. Most of the other shops won't have anyone in the water with you (at least not the last time we dove in the Keys - it's been a couple of years).

Also remember that you may be weighted perfectly but if/when you get anxious and start to breathe wonky (hyperventilate, etc) it'll screw up your buoyancy and you may begin to float up. With less than 25 dives I wouldn't be surprised if you fall into that category. My husband and I were grossly overweighted when we first started diving in the Keys (our first salt water experience) - out of an overabundance of caution.

Good luck and have tons of fun!!

 

[EFX]

I have a 6lbs plate and dive with zero additional weight. I would go with your plan to put one 2lbs weight in each pocket. It’s always better to be s little heavy. If that goes well on the first dive, you can probably pull one or both of them on the second dive.

Agree.