BP/W Questions

[ppo2_diver]

You'll probably get both AL and Steel plates. Keep in mind that as neoprene compresses, it will affect your buoyancy. A steel plate can quickly overweight a diver at depth when a wet suit compresses.

 

[opperud]

I was hoping I could get some help / opinions with possible rig selection. I currently dive with a jacket BC, and am looking at launching into DIR / GUE diving and thus need a whole new setup for both myself and the wife.

I am 176cm (5'10") and weigh 80KG (176lb's). I dive here in Melbourne in a 7/5mill semi dry with 10L and 12L steel singles (I believe these are equivalent to your Steel 80's and 100's) depending on what I rent from the shop. (Untangling cubic feet, litres, PSI, bar for scuba tanks and RMV / SAC calculations [Archive] - ScubaBoard is a good reference).

I am thinking about doing drysuit diving in the winter, however that's not the deciding factor in equipment choice.

More important, is that I do a lot of warm water diving, which is generally AL80's and 5mill steamers or shorties. And I want to move into doubles eventually as there is a lot of deep wreck diving around here. What I'm looking for is the most flexibility out of a rig, with the least amount of "wasted" purchases.

My questions are around
a) Plate - Al or Steel. Obviously Al travels easier, but will it be too light for true GUE style diving in colder waters with the thicker suits?
b) Should I just get a steel plate and a soft / plastic travel plate for warmer weather diving?
c) Wing size(s) - I have no idea where to start, no matter how much I read. Or style
d) Wing type - some manufactures have wings they claim suit singles AND doubles. Any opinions? Am I choosing the worst of both worlds?
e) Single tank Adaptors - or some manufactueres claim their wings don't need them. Any opinions?
f) The Hog harness - i've heard that it doesn't suit women as much as men (damn breasts!). Any comment? Maybe we can get her a harness setup that may not be strict DIR but would be at least a BP/W and not a jacket

Confused

Hi OzGriffo!

Unless you are one of those guys that needs extremely little weight/lead to be correctly weighted and you are planning to dive a drysuit, I would suggest you go with the ss plate. Aluminum is nice if you travel a lot, but in general it makes more sense to buy gear for where most of your diving is. The savings are not significant either way.

About wing size. The size/lift capacity of your wing is a function of your weight of gas, and the shape and size (not weight) of your tank/s.
If you are correctly weighted, regardless of how big/heavy your gear are at the surface, you are neutral in the water when your tank/s is empty or close to empty, your wing is empty, and your suit holds only enough gas not to squeeze you.
The wing needs to lift the weight of your gas when your tank/s are full, and your head out of the water. Air/nitrox in a 12L/232bar tank will be about 3kg and your head is about 5, add some regs, hood, mask.... and the top of your tank/s to a total of let's say 12 for singel and 14-15 for doubles. For single 12 a 30" wing will be sufficient and for the majority of doubles a 40" will be sufficient with regards to lift capacity. If you are diving stages, the wing should also be able to carry their weight of gas. A 40" will still work
The other thing that is relevant to your choice of wing is the actual size and shape of your tank/s. A single tank wing may very well have enough lift for a set of doubles, but will not work very well simply because it will be too narrow. The lift, or at least most of it needs to be on the side of the tank/s rather than between them and you. The same is true for bigger (wider) and smaller (narrower) sets of doubles.
For bigger (than D12/alu80) doubles, you will likely use a heliumbased gas, which is lighter that air/nitrox, so weight of gas is rarely a problem.
A couple years ago I brought (by mistake) my 40" wing along to Italy for a week of diving. We dived D16 for the duration of the trip and while that was not an issue with regards to lift, it was a little uncomfortable when filling the wing at the surface, having the argonkit and cannister dig into my ribs
Personally I use a 30" for singel, 40" for D12 and 55" for D18 and that has always worked very well for me
You can use a bigger singeltank wing (40") for small and narrow (D7-8,5) doubles, but unfortunately, that's as close as you get to a "one size fit's all" wing

Women in one piece harness is absolutely no problem whatsoever. I have many female divebuddies, I routinely have female students in my classes, they all dive one piece harnesses and I have never had an issue with it


Best,
Bjørn

 

[halocline]

You'll probably get both AL and Steel plates. Keep in mind that as neoprene compresses, it will affect your buoyancy. A steel plate can quickly overweight a diver at depth when a wet suit compresses.

This is a bit of a nonsensical statement. The ballast provided by a steel plate is exactly the same as any other ballast in terms of how it reacts with depth and wetsuit compression. Any diver wearing neoprene will become more negative as their suit compresses. That's why we use Buoyancy Compensators. As a "tech instructor" you should know better.

 

[Tortuga68]

...not to mention that the difference between SS and alloy plates is only ~3#

 

[ppo2_diver]

This is a bit of a nonsensical statement. The ballast provided by a steel plate is exactly the same as any other ballast in terms of how it reacts with depth and wetsuit compression. Any diver wearing neoprene will become more negative as their suit compresses. That's why we use Buoyancy Compensators. As a "tech instructor" you should know better.

You're assuming people weigh themselves correctly. Many people overweight themselves at the beginning of a dive. What happens if/when the BC fails at depth then?

 

[Couv]

You're assuming people weigh themselves correctly. Many people overweight themselves at the beginning of a dive. What happens if/when the BC fails at depth then?

.....they ask the Tech Instructor who did not teach them correct weighting procedures for a refund.

 

[knowone]

http://www.google.com.au/url?sa=t&rct=j&q=weight%20of%20a%20head&source=web&cd=4&ved=0CEcQFjAD&url=http%3A%2F%2Fwww.guardian.co.uk%2Fnotesandqueries%2Fquery%2F0%2C%2C-1244%2C00.html&ei=_SHETu7rI62TiQezg_XwDQ&usg=AFQjCNFYWrKxFX8yJzEeYIEaTpn2Z3UW8Q

 

[Griffo]

Thanks to all for the comments, idea, tips, and recommendations. I think someon even mentioned to get in contact with Nick from GUE - which will be happening shortly. One thing i've quickly learned with diving though is to get lots of peoples advice, as everyone has their own personal preference. And sometimes that can be out of step with the majority, which is why I thought this thread would add value.

So I think i've learnt that
a) the bit I read about women and harnesses is complete bs
b) go the stainless plate and a wing around 30 lbs, with no STA needed.
c) Weighing your head while it's still attached to your body is harder than I'd have imagined

I should just also point out that whatever you pay for diving gear, the price in Australia is often double. So buying over the Internet is very attractive, but makes trying on and testing kit somewhat harder than going to the LDS.

Thanks All

 

[halocline]

Weighing your head is easy. Just go to the supermarket and find a ham just about the same size...you can have someone hold it up next to you for comparison. Buy the ham, put a wig on it, maybe some glasses and there you go, close enough!

 

[Griffo]

OK I have another couple of stupid questions. I've been looking at the Dive Rite and HOG gear, for no other reason than it seems to be competitively priced, easy to source over the net, and has a good rep here. Happy to look at anything else that people recommend, but I'm trying to limit the number of brands I look at as the more I look the more my head hurts with options

So...
a) Backplate pads - are these to be recommended? I'm buying a setup for both me and the wife, she is most likely to want the padding benefit
b) Should I look at a backplate pad that also holds an SMB? The HOG one isn't even described on their website, so not sure if it holds an SMB.
c) The Dive Rite pad seems to be held on by looping through he straps. Everyone else seems to screw them to the backplate. This doesn't sound very secure, or does it make life cleaning etc much easier?
d) Weights - this is where i'm really confused. Nick told me to look at tank weights and weight pockets. Neither brand does a tank weight system (does only Halcyon do this??). DR does a weight pocket, but it seems expensive to me. The whole weighting system in the GUE system still confuses me. What should I be looking at buying? Assuming I wear 24lbs with my current setup, and the plate weighs 6, do I need enough pockets for 18lb's? Or am I missing something
e) The wife is 5'4". Will a standard plate be OK, or should I be looking at a brand that makes different sizes?