Not having dumpable weights on BPW

[JLRO22]

I am super close on clicking order on my BPW set up. But I'm starting to get skeptical on the weight set up.
I'm a small diver 5'2 and only 115 lbs. I dive temperate waters in California with a 7mm suit, 5/3 hood, 7mm boots etc. This is my current 'possible buy' list in terms of main weighting:

Backplates​

• Halcyon - Small Stainless Steel Backplate; 4.05 lbs
• Dive Rite - Short Stainless Steel XT Backplate; 5.41 lbs

STAs​

• Dive Rite - STA; 0.81lbs
• Halcyon - STA; 2.4 lbs
• Halcyon - STA w/ weight; 7.55 lbs

With my dive program, I have access to AL80s or Steel 85, 80, 100s but usually opt for a steel more often times than not. Its a bad day if I have to use an AL80 or there's no steels left and I need more air than what's in an 85.
Anyway my dilemma is what is correct configuration without it being dangerous of having too much non-dumpable weight on my body? Since I dive steels usually, if I run a set up that's heavy (DR plate w/ any of the STAs), I would barely have to put anything on a belt. And if I need to do an emergency ascent and I dump, I'll be dumping basically nothing and need to instead kick like hell. Yeah that means I'll means I'm probably overweighted, but is running 7 or even 12 lbs + a steel over kill for such a small diver. Is it safe to run all your weight on your back?

Thanks in advance!

 

[PamelaH]

I am super close on clicking order on my BPW set up. But I'm starting to get skeptical on the weight set up.
I'm a small diver 5'2 and only 115 lbs. I dive temperate waters in Monterey with a 7mm suit, 5/3 hood, 7mm boots etc. This is my current 'possible buy' list in terms of main weighting:

Backplates​

• Halcyon - Small Stainless Steel Backplate; 4.05 lbs
• Dive Rite - Short Stainless Steel XT Backplate; 5.41 lbs

STAs​

• Dive Rite - STA; 0.81lbs
• Halcyon - STA; 2.4 lbs
• Halcyon - STA w/ weight; 7.55 lbs

I'm similarly fun sized and dive with a BPW set up. I gave up on dumpable weights and just wear a belt. There's not enough real estate between the rig and my body to fit a weight pocket and it made getting into my gear a PITA. Just use 2 weights, one on each side and you'll be fine. Way easier.

 

[JLRO22]

I guess it not really a thing of having dumpable weight pockets but weight I can just shed off in general even on a belt. Like if I only need like 6 lbs on a belt, is that consider enough to shed off and make an effective emergency ascent?

 

[MB NZ]

I've dived without ditchable weight for the last 20 years in both wetsuits and drysuits. If you are weighted correctly, you will not be pinned to the seabed in the event of a catastrophic BCD/wing failure, even in a wetsuit. Freediving opened my eyes to the buoyancy of a human body covered in 7mm neoprene. Regardless, I'm more concerned about accidental loss of ditchable weights than non-ditchable weight in recreational SCUBA diving. The choice is yours to make.

 

[Tigerpaw]

A solution could be to carry with you a SMB or two, they should provide you with enough lift to get you to the surface in an emergency but you'll have to practice so that you won't be rocketed to the surface.

Finally, if you are weighted correctly you should be fine. My sidemount setup has weights that are non ditchable. So what I did was just dive, dive and dive until I was sure and comfortable of my buoyancy. I'm pretty confident that I can surface safely in an emergency in sidemount.

I also keep notes on my body weight, wetsuits (3mm or 5mm), the type of undergarments I use with a drysuit and whether I'm using aluminum or steel tanks. I personally try to dive as light as possible but that is my preference. 12 pounds of weight at 115 pounds body weight does seem like ALOT weight. For reference I'm 260 pounds and I dive with 0 - 2 pounds in my 3mm and aprox 6 pounds in a 5mm in fresh water with aluminum tanks.

Be sure of your buoyancy, make changes and dive. Good luck!

 

[MB NZ]

Here's a thought for the OP, buy your new toys, get weighted correctly however you choose to do it, descend to the sea bed at the deeper end of your diving depth range and completely empty your wing of gas. See how it feels. If you're still uncomfortable with the idea of non-ditchable weight, then you can look at ditchable weight options. There are various contraceptions on the market that would suit your needs.

Edit: Regarding correct weighting, I see you dilemma. Whichever route you choose, don't be over-weighted, that is never a good thing. I know there is a lively dive scene in California, can you try before you buy and do a proper weight check?

 

[inquis]

if I only need like 6 lbs on a belt, is that consider enough to shed off and make an effective emergency ascent?

I should hope so, and that's probably too much to dump in many cases. If properly weighted in a 7mm, you should be neutral around 10 ft at reserve tank pressure and empty wing. If you are at the end of a dive near reserve pressure and dump 6 lbs, you will be +6 lb buoyant at 10 ft and accelerating up. Not what I'd call a controlled ascent.

On the flip side, at the beginning of the dive, you should be negative at 10 ft by the non-reserve gas you still have (max of 5 lb in AL80, 7 lb in an HP100, and less as the dive progresses). At 100 ft depth, wetsuit compression might lose another 6-7 lb for someone your size.

Total of 14 lb negative. A large breath might add 6 lb for you. Can you kick up an additional 8 lbs until your wetsuit expands? I suspect so, but feel free to test it. If you can't, then you need a solution, and ditchable weight is one of several options.

 

[rjack321]

How much lead are you using now? Are you really diving a 7mm suit with 6lbs of weight (total) in saltwater?

The 85 is neutral or close to it when empty. I would expect with the SS plate + a non-weighted STA you might still need about 6-8lbs on a belt on top of the 6lbs for a plate and STA. So 12 to 14lbs total in salt and about 5-6lbs if you went to Lake Tahoe in that 7mm suit/hood/vest.

I would skip the ridiculously overpriced weighted STA unless you end up in a drysuit with alot more lead

 

[lowwall]

You don't need an STA with either of those plates as long as your wing has slots in the right place for the tank bands. What wing were you planning on buying?

You need to get your weighting figured out with your new BP/W before you start considering ditchable versus nonditchable. If I were in your shoes, I'd start with your preferred plate with no STA and a weight belt on to which I'd put two small trim pockets where you can reach them. If you can't borrow any, these are $12 each and will work fine. FWIW, I use a pair of these on my waist belt to hold any needed lead.

XS Scuba Single Weight Pocket

Does your tank get to buoyant near the end of a dive and you keep getting banged in the head from the valve, or maybe you would like to relieve your hips from all that weight from your weight belt or...

www.scuba.com

Put a pair of 1 or 2 pound weights in each pocket for 4-8 pounds total. When you get to your safety stop, assuming you are at somewhere around 500-800psi, you can experiment by removing weights until you are neutral with a completely empty wing. It's easiest to do this with a helpful buddy, but you can rig up a lift bag or DSMB to temporarily hold the weights if you have to.

You really only have to do this with one tank size. The empty bouyancy for all tanks is published somewhere, so you can add or subtract relative to your known tank.

Now that you know your correct weighting, follow @inquis' suggestion and test whether you are comfortable swimming it up. You do this just after the descent on a relatively deep dive so your tank is still pretty full. Get vertical, dump all the gas from your wing and see how hard it is to ascend. If you didn't want to waste the dive on a straight bounce dive, you could take it maybe 1/3 of the way up and then hold that depth for another minute or so to give you a really good idea of the effort required.

If you feel the effort is uncomfortably high, then you know you need some ditchable weight. If not, then you don't. Although you still might want some given that you dive a 7mm. If you have to take off your rig at depth due to entanglement or at the surface for any of a myriad of reasons, it's a lot easier if you aren't super bouyant while your rig is super negative.

At this point you'll also have enough info to decide on the weight of the STA if you still want one. Note that you can also get a lightweight AL STA that adds only a couple of ounces of negative bouyancy.

 

[happy-diver]

When I need extra weight rather than making the breathing apparatus unmanageable
it goes in a flat ingot belt that does not interfere with the plate and is not for ditching