Weighting system and lift for cold water compatible BP/W.

[axluba]

Dear all,

It is time for me to buy my first BP/W. I am pretty much set on a manufacturer (because they have all I need, they have been extremely helpful and the price is right for me). But I need some advice on the weight system and wing capacity needed.

For financial reasons I need to have ONE versatile rig that would:

- Dive in cold water (3c-37f)
o Very thick wetsuit (10-13mm)+hood, gloves, boots until I get trained on Dry-suit
o Dry suit
o Steel tank

- Travel in a carry-on luggage

- Dive in warm water (24c-75f)
o Thin wet suit

So I will get an Aluminum backplate and associate it with a weight system including trim/non ditchable weight and ditchable weight.

I know this is not IDEAL (s/s would be better for cold water) but I believe that it would do everything I need well enough so that I can really enjoy my dive whether in cold or warm waters.

Now my questions are simple to formulate:


- What wing size should I get: 14L (31lbs) or 17L (37lbs)? Mostly to compensate the compression of that huge amount of neoprene I carry. I don’t want my wing to taco too much but I also want to be able to dive safely

- How much DITCHABLE weight do I need? I will have the opportunity to add trim weight to the backplate as well (more than enough) but my question is how much of it should be ditchable? No necessarily a number but more a way to calculate it (worst case scenario would be In case of wing failure early in my dive I think)

As a reference I dive in that cold water/thick wet suit with a rental BCD and I barely manage to go down with 8kg (17.6lbd).

Et voila! These are my questions, do not hesitate if you need precisions or clarifications on some points.

My goal is to buy my rig with the right wing and the right ditchable weight system size for the conditions I described above.

I would really appreciate any input as I would like to buy the wing fairly quickly and I realize that I miss some key points.

Thank you for reading me!

 

[rob.mwpropane]

I dive a VDH 35lb wing w/SS bp in all the conditions you posted. I dive 7mm farmer john (14mm core) when wet and cold water. I travel with it to FL, have taken it on planes. No issues whatsoever. Have been very happy with. I use anywhere from 0-20lbs depending on where I'm diving and which exposure suit.

A SS bp is only 3lbs or so heavier than al, so I would just stick with SS if your doing any cold water stuff. When I dive warm I don't have to wear any weight, but I don't feel "heavy".

I think your over thinking this a little (which is way better than under thinking it!). I would get your rig all together and see how much weight you need. Dive it and see how hard it is to swim up from depth without any air in the wing, then decide how much needs to be ditched to suit YOUR needs.

No matter what you buy, chances are you'll change a lot of things along the way, at least with a bp/w those changes won't be as expensive.

 

[axluba]

Thanks for your input!
Overthinking sounds like something I would do. However, the goal here isn’t to have it perfect from the first go but more to have it good enough to be able to dive safely without needing to re-invest in different bp/wing parts/accessories right away.


It has been pointed out to me in another thread that in case of wing failure early I would have to fight off the weight of my almost full steel tank as well as my rig/backplate weight, without the buoyancy help of my, then compressed, suit. Which makes some good sense and therefore has me look a bit deeper into the amount of weight that I should be able to ditch.


Also the 3 pounds added to the backplate can have a significant impact when traveling only with a carry on. Finally I see the option of ditching weight (if there are properly secured) always safer than not having this option. Those ditchable weight system are the most expensive part of the rig after the wing so I’m trying to get in the right ball park before paying. (They exist in both 4lbs/pocket or 8lbs/pocket) I was leaning toward the smaller ones


Regarding the wing I lean toward17L for the “safe” side but I welcome all inputs (especially because the 14L is discounted )

 

[Fastmarc]

Here is a great spreadsheet that will help. It's simple enough to figure out, but It has a tutorial that not only will help, but has great info.
Optimal Buoyancy Computer

 

[axluba]

Here is a great spreadsheet that will help. It's simple enough to figure out, but It has a tutorial that not only will help, but has great info.
Optimal Buoyancy Computer

thanks I'll be studying this carefully tonight!

 

[rob.mwpropane]

It has been pointed out to me in another thread that in case of wing failure early I would have to fight off the weight of my almost full steel tank as well as my rig/backplate weight, without the buoyancy help of my, then compressed, suit. Which makes some good sense and therefore has me look a bit deeper into the amount of weight that I should be able to ditch.

I still think it'd be wise to swim the rig to depth release all air and try to swim up. Use a weight belt and maybe you can drop a weight or 2 on the platform and go from there. I think you'll be surprised at what it feels like (if your properly weighted) to swim everything up from depth.

Also the 3 pounds added to the backplate can have a significant impact when traveling only with a carry on. Finally I see the option of ditching weight (if there are properly secured) always safer than not having this option. Those ditchable weight system are the most expensive part of the rig after the wing so I’m trying to get in the right ball park before paying. (They exist in both 4lbs/pocket or 8lbs/pocket) I was leaning toward the smaller ones
Regarding the wing I lean toward17L for the “safe” side but I welcome all inputs (especially because the 14L is discounted )

I have zero issues with it in a carry on, but to each his own.

Personally I have 2 sets of pockets (smaller / larger). If I had it to do over I would probably just use more of the smaller so I could trim out a little better. I rarely use the larger unless with a drysuit.

I use these;
7.25kg/16lb Removable Weight Pockets
Deluxe Small Weight Pocket

 

[axluba]

I still think it'd be wise to swim the rig to depth release all air and try to swim up. Use a weight belt and maybe you can drop a weight or 2 on the platform and go from there. I think you'll be surprised at what it feels like (if your properly weighted) to swim everything up from depth.



I have zero issues with it in a carry on, but to each his own.

Personally I have 2 sets of pockets (smaller / larger). If I had it to do over I would probably just use more of the smaller so I could trim out a little better. I rarely use the larger unless with a drysuit.

I use these;
7.25kg/16lb Removable Weight Pockets
Deluxe Small Weight Pocket

I will definitely give it a try! and thank you for sharing the type of gear you are using. it gives a good indication (and it is fairly similar to what I was looking at) I will probably check the larger quick release weight 8lbs/pockets which are closer to what you are using.

 

[rob.mwpropane]

I will definitely give it a try! and thank you for sharing the type of gear you are using. it gives a good indication (and it is fairly similar to what I was looking at) I will probably check the larger quick release weight 8lbs/pockets which are closer to what you are using.

My gear is not the end all be all. It's just what works for me (for now). Plenty of ways to do it though.

Also you could see what people are diving in your area. Might give you better ideas. I don't mean what the shops are selling, I mean what people are actually using....the people not in the OW / AOW class, lol

 

[axluba]

My gear is not the end all be all. It's just what works for me (for now). Plenty of ways to do it though.

Also you could see what people are diving in your area. Might give you better ideas. I don't mean what the shops are selling, I mean what people are actually using....the people not in the OW / AOW class, lol

I know, not saying that this is the kind of weight system I'm going to take just because you have it. I just take every input into account. thank you for sharing yours!


the people here aren't really diving, especially at that time of the year, in the small lake I live by... Outside of my instructor (who's taking a rental BCD when he's not diving his double bladder OMS on doubles). the bright side is that I get private lessons even when we just go for fun. the down side is, not many other divers of my level. 3 Celsius right now! makes for fun dives!

 

[tbone1004]

@axluba I would get a SS plate. It's better than AL for warm water single tank diving unless you can't deal with the extra kg of weight when you travel.

Your real issue is the 10-13mm suit which makes the wing size requirement significantly larger than it would be in a drysuit or reasonable thickness wetsuit. I dive a 30lb wing for all single tank diving, but I don't dive anything thicker than a 7mm *non farmer john*.