Info Beginners Guide To BP/W

[loosenit2]

Are most steel plates pretty similar? I assume they all allow use of standard 2" webbing as an industry standard. But beyond that, do certain models offer more or less features? I'm looking at the Dive Rite and Hog SS plates online and the Hog plate is about $50 less. Compared to other OEMs there's upwards of a $70 difference. Is there enough quality or option differences to warrant the big price differences between manufacturers of these plates?

there are some different thicknesses and weights out there, as well as some slightly different cut out designs. Overall they are mostly similar. The different brands may have hole patterns that best line up with their wings. For example if you look at the HOG and OMS ones they has 3 holes along top center for adjustments, the DGX and dive rite have 2.

Don’t over spend on a backplate, the DGX and HOG are both good.

 

[RobPNW]

Question about using a weight belt with the BP/W... I would prefer to not have a weight belt but I may end up using one, at least with a small amount of weight to allow me to get a medium size wing to can be dual pursued for cold and warmer water. With the weight belt, that will allow me to float my kit without needing something like a 40lb wing or bigger in cold water. I can see advantages and disadvantages of wearing the weight belt over or under a crotch strap. Is there a standard practice? Seems like it would matter if there was a QR on the crotch strap or not.

 

[rjack321]

Question about using a weight belt with the BP/W... I would prefer to not have a weight belt but I may end up using one, at least with a small amount of weight to allow me to get a medium size wing to can be dual pursued for cold and warmer water. With the weight belt, that will allow me to float my kit without needing something like a 40lb wing or bigger in cold water. I can see advantages and disadvantages of wearing the weight belt over or under a crotch strap. Is there a standard practice? Seems like it would matter if there was a QR on the crotch strap or not.

Weight belt goes under. Both buckles are right hand release.
Your kit needs to float without you in it.

a 40lb singles wing is not really a ginormous thing BUT getting one BC to do everything is pretty much the antithesis of a BP/W.

Al plate and 20-24lb wing for tropical diving (minimal baggage weight and minimal wing)
SS plate and 32-40lb wing is nicer when you have a a drysuit and a bunch of lead.

 

[apenland01]

Weight belt goes under. Both buckles are right hand release.
Your kit needs to float without you in it.

a 40lb singles wing is not really a ginormous thing BUT getting one BC to do everything is pretty much the antithesis of a BP/W.

Al plate and 20-24lb wing for tropical diving (minimal baggage weight and minimal wing)
SS plate and 32-40lb wing is nicer when you have a a drysuit and a bunch of lead.

I guess this would depend on whether your priority was dumping weights or removing your kit...

 

[rjack321]

I guess this would depend on whether your priority was dumping weights or removing your kit...

Trust me on this one

Weightbelt goes under. Its still easy to ditch

 

[drewski_SF]

<snip>
I could shift ~10 lbs from the integrated weights on the rig to a weight belt and drop down to a 30 lb wing, but then my options for adjusting trim or shifting weight between the rig and weight belt would be fewer than with the larger wing
<snip>

Can you explain more how shifting weight from integrated to weight belt would reduce the wing lift needed from 40lb to 30lb?

It seems like it would change the trim, but you'd need the same lift wing regardless of where you keep the weight?

 

[mc42]

Trust me on this one

Weightbelt goes under. Its still easy to ditch

No question - weight belt under, same right-handed release as the harness.

If that makes you worried, consider that you should have a balanced rig, so ditching weight is the least preferable option compared to just swimming upwards if there is a problem with your buoyancy control. That means finning up against the weight of the air in your tank.

If you must ditch weight, you'll need to undo your harness buckle, pull the belt through the crotch strap loop, releasing the crotch strap, then the weight belt will drop pretty easily.

 

[RobPNW]

Can you explain more how shifting weight from integrated to weight belt would reduce the wing lift needed from 40lb to 30lb?

It seems like it would change the trim, but you'd need the same lift wing regardless of where you keep the weight?

If I'm in a drysuit, with no weight belt, and no kit on, I am positively buoyant. If I carry X amount of negative buoyancy on the kit, I need X+ some safety amount of lift to float the kit at the surface if I have to. The total weight, including on a weight belt, would cancel out your buoyancy, with an empty wing, and allow you to sink. The bottom line is your adding weight everywhere to allow you to sink. You're deciding on an amount of wing lift that will allow you to float the kit and everything on it, including any weights. Remember, you're doing a weight check with an empty wing, empty lungs, a nearly empty tank and you're JUST sinking.

With all that said, you are going from basically neutrally buoyant at the surface with a near empty tank and an empty wing, to negatively buoyant as you descent. That amount of negative buoyancy is equal to the water weight of the volume reduction of your exposure suit as it compresses with depth. How much that is I'm not sure, but it's not 30-40 lbs. And as it happens, you're offsetting by adding air to the wing and drysuit.

I hope that made sense. LOL.

 

[RobPNW]

No question - weight belt under, same right-handed release as the harness.

If that makes you worried, consider that you should have a balanced rig, so ditching weight is the least preferable option compared to just swimming upwards if there is a problem with your buoyancy control. That means finning up against the weight of the air in your tank.

If you must ditch weight, you'll need to undo your harness buckle, pull the belt through the crotch strap loop, releasing the crotch strap, then the weight belt will drop pretty easily.

I realize that a QR buckle on a crotch strap is a potential thing to fail. But would a QR on the crotch strap make it easier to ditch the weight belt? It seems like it would.

 

[mc42]

Can you explain more how shifting weight from integrated to weight belt would reduce the wing lift needed from 40lb to 30lb?

It seems like it would change the trim, but you'd need the same lift wing regardless of where you keep the weight?

Sure - Let's say I need 28 lbs of total weight when I use my AL80s. This includes 6lbs from the backplate. I can choose where the rest of the 22lbs goes - whether I wear it on my weight belt, put it in trim pouches, or integrated.

So I actually only need a 30 lb wing (28 lbs, really, but good to have some extra margin) to float the total combination of me, whatever weights I add, the rig, and tank.

Now, the extra lift required with the integrated weight is purely to ensure that the full rig with weights should be able to float on its own - you don't want to lose it if you drop it in the water, and it would be extremely awkward, dangerous even, as you would be relying on your exposure suit's buoyancy to offset the negative buoyancy of the rig (!).

So if the 10 lbs are moved from weight belt to rig, the wing needs to have that additional (excess) lift to float the rig, so 28lbs + 10lbs = 38lbs required for the wing. The minimum lift required of 28lbs doesn't change in either scenario.