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Yet another BPW question

Discussion in 'Basic Scuba Discussions' started by cainslie, Nov 30, 2018.

  1. cainslie

    cainslie Angel Fish

    # of Dives: 500 - 999
    Location: Ballito, South Africa
    Hi All.

    TL;DR: Ali or SS backplate?

    I've searched, I've read, I've Googled & I've Youtubed. I've learned a LOT, but I have just one more question... :)

    Firstly though, some background which will help:
    • I dive warm(ish). Generally, around 18 to 20'C, but frequently 16'C - 23'C. (East coast of South Africa).
    • I wear a 5mm wetsuit which is getting old, has a little less buoyancy than new, but will be replaced with another 5mm one day.
    • Almost all my dives are with a 15L steel (232bar) and occasionally I use my 12L.
    • Have only ever dived ali tanks when travelling and then I use rental gear anyway.
    • I have a few stab jackets - Cressi, Scubapro and Tigullio.
    • In all cases, I dive with 4kg of lead.
    • Recreational diver only. Sadly, too claustrophobic for any serious overhead diving.
    • 70% of dives are around 27m (90'), the rest are closer to OW limits.
    • I do plan to do some Tec training - very specifically for depth as there are deeper wrecks in the area that I'd like to explore. I expect that in the next 5 years I'll be diving 2 specific wrecks at 100m (330') and then I hope to dive with the coelacanths (about a 4-hour drive for me).

    So, all that out the way, next up for me is a BP/W, DIR setup for my 15L steel. 12L doubles in a year or so, but don't worry about that, it'll require a new wing anyway.

    Considering my current setup, do I get an ali or SS plate? I'll be looking for a 14kg (30lb) to 18kg(40lb) wing, I think. Most advice I find relates to drysuits and ali tanks so I'm struggling to find sense in it all. There isn't a lot of this kind of gear in South Africa and certainly not enough of it around for me to be able to borrow, test, try out etc. Along with the FOREX rates, getting it wrong will be a very expensive mistake.

    So, ali or SS?
    Feel free to jump in with any other comments, questions or knowledge. Moving to BP/W is the next step for me, I just don't want to make stupid (read: expensive) mistakes.

    Thanks very much!!
  2. happy-diver

    happy-diver Skindiver Just feelin it

    # of Dives: 2,500 - 4,999
    Location: same ocean as you
    superheavydeathmetal likes this.
  3. Zef

    Zef Divemaster

    For you, based on the stats you listed, either would work....if you go with SS you could probably drop 2kg of lead, especially if you with a basic harness system as it will not add positive buoyancy to your setup. BCs tend to be floaty so some of your lead is being used to offset that, when you switch to BP/W + harness that is factored out by the gear choice.

    If you are going to be traveling and want to take your BP/W along, then an Aluminum plate would be beneficial from a packing weight standpoint...you will just need to add weight to compensate for the tank you will be using and how buoyant it is at the end of the dive at +/- 500 psi (30-50 bar). With an aluminum plate you will need a bit more lead than a SS plate and that can be worn as ditchable or static weight.

    How buoyant, positive or negative, are your tanks towards the end of your dives? If they are significantly positively buoyant and you don't do a lot of airline travel where weight is factor then I recommend SS for its robustness, versatility, and the fact that you will not need as much added lead.

    When I switched from a BC to a SS BP/W I dropped from 6kg additional lead to between 1 and 2kg with a 5.5mm wetsuit. At the beginning of the dive I don't need any weight but I do to offset the nearly empty tank I use.

    There are some inexpensive plate options out there, so if you don't have travel plans now but you get the bug in the future you can pick up an aluminum plate new for between $75 and $100 (DGX, Deep6, HOG as examples)...you can rig a simple hogarthian harness rather inexpensively or you can transfer your harness from one plate to the other to save some cash.

    Hope that helps.

  4. JamesBon92007

    JamesBon92007 Great White

    # of Dives: 2,500 - 4,999
    Location: Southern California...too far from the ocean
    Personally, I like having some of the weight in the backplate. After diving with no weight belt (tropics) I much prefer it. On my trip last month I had my SS backplate and 14 pounds of lead in the pockets. Next week I'll be diving with my plastic backpack filled with 8 pounds of lead shot plus I'll be wearing about 16 pounds of lead in my pockets (I'll be wearing a thicker wetsuit). If you guys don't hear from me by about December 14th then it didn't work.
    KWS likes this.
  5. almostDIR

    almostDIR Barracuda

    # of Dives: 25 - 49
    Location: Finland
    I would go with a 3mm stainless steel plate , add two weight pockets on the tank straps for quickly adding a little bit of additional weight if needed. If you need droppable weight pockets you could add them as well. but I would not use the 6mm plate as a starting point, I think a 3mm would be perfect (can take about 2kg lead off and not overly heavy for traveling) and you can always add normal weights to the pockets (easy to rent if travelling) and if needed a P-weight is always an option as well :)

    I don't see much use for a aluminium backplate unless skin diving in tropics or travelling with it all the time. you can of course compensate the weight difference with lead but if you need lots of lead anyway it is less practical choice I than steel I think
  6. Satrekker

    Satrekker Barracuda

    # of Dives: 200 - 499
    Location: Clearwater, FL
    with a 5mm wetsuit, I'd definitely go stainless. from your specs, it looks like you'll still be carrying a bit of lead, but it's better to have the weight distributed over your lungs in the backplate instead of on a belt. Also, when you buy your wing, make sure it is large enough to float your rig with a full cylinder. I think 30lb will probably be the way to go for your. 40lb, at first glance, appears to be too much imo. GL
    KWS likes this.
  7. Zef

    Zef Divemaster

    When I was buying my BP/W the advice I received from DGX for single tanks was basically that too large a wing will cause lots of drag in the water and taco around the tank which can cause issues with venting air from the wing. For single tank diving get a single tank wing. If you plan to dive doubles then get a double tank wing.

  8. Jackie Treehorn

    Jackie Treehorn ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 200 - 499
    Location: Between Mikes and Weekapaug
    SS makes good sense. I picked up an Apeks SS plate to replace my BC and I dropped the 4kb of lead I would carry and now i'm just a tad overweight.

    Sounds like you don't fly with gear. So to me, its a no brainer. I fly with my SS plate without issue. :)

    Planning to get down to 330 feet?? That's pretty darn deep and I think you were referring specifically to caves, but that sounds like serious overhead diving to me. That SS will also serve you well as the core for your future doubles setup.

    Good luck!
  9. KWS

    KWS ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 500 - 999
    Location: SE TEXAS
    I have always heard the rule of thumb steel tanks= al plate and al tanks= steel plate. I have not made that work in practice. i use steel and steel in FW. I would say that doubles may be a different animal. let alone differences in wet suits or dry suit. just run the numbers and see what you need for weight and whether you want it in you BP or on a belt. a little ditchable weight is fine.
  10. EireDiver606

    EireDiver606 Public Safety Diver

    It’s hard to know. I personally would go with SS. But if you go to D12s next year, the aluminium plate would be better, especially if you stick with D12s. Ali is better for travelling. Also, you’re slightly overweighted I think. It depends, but you normally shouldn’t need 4kg with 5mm wetsuit if diving with steel 15L. If you get SS plate, you should need no or almost no weight.

    Secondly, stop diving 15l single, they’re horrible tanks to dive with. Too unstable. If you’re used to diving with 15L, then D12s will feel so stable, wait till you see!

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