Which rig do I need?

[Rand]

Tobin,

As per our phone conversation, I did a buoyancy check with just me in my drysuit with heaviest undergarments.

It took 24lbs to sink me and it in fresh water.

I'm sure you get tons of calls and I don't expect you to remember everyone, so here's my info again.

Height: 5-06
Weight: 160
Most buoyant exposure suit: shell drysuit (24lbs to sink in fresh water)
Tank: single HP100 steel (manufacturer XS)

I will be using the BP/W for training in the quarry with the drysuit, as well as some cold water wreck dives in the ocean.

I also will be using it for travel to warmer salt water with a 3mm wetsuit and rented AL80 tanks. (We talked about this setup and I think the SS plate would be enough without additional weight)

I just need to know what size wing you suggest.

I also wanted to know about the harnesses. I have heard that there is a technique for getting into/out of a Hog-type harness. What is the technique?

Also, given that I will be going from drysuit to thin wetsuit several times a year, would it be better to go with the Pro-fit harness, or is the Hog-style harness not that hard to adjust for different exposure suits?

Would you suggest that I get the bolt on weights for the plate for when diving with the drysuit? I have read in some of your posts here that you sometimes tell customers to try out the wing with just a weight belt first and then order the bolt on weight later if needed.

Thank you for all your help.

I will be ordering as soon as I get your recommendations.

 

[cool_hardware52]

Tobin,

As per our phone conversation, I did a buoyancy check with just me in my drysuit with heaviest undergarments.

It took 24lbs to sink me and it in fresh water.

I'm sure you get tons of calls and I don't expect you to remember everyone, so here's my info again.

Height: 5-06
Weight: 160
Most buoyant exposure suit: shell drysuit (24lbs to sink in fresh water)
Tank: single HP100 steel (manufacturer XS)

I will be using the BP/W for training in the quarry with the drysuit, as well as some cold water wreck dives in the ocean.

I also will be using it for travel to warmer salt water with a 3mm wetsuit and rented AL80 tanks. (We talked about this setup and I think the SS plate would be enough without additional weight)

I just need to know what size wing you suggest.

I also wanted to know about the harnesses. I have heard that there is a technique for getting into/out of a Hog-type harness. What is the technique?

Also, given that I will be going from drysuit to thin wetsuit several times a year, would it be better to go with the Pro-fit harness, or is the Hog-style harness not that hard to adjust for different exposure suits?

Would you suggest that I get the bolt on weights for the plate for when diving with the drysuit? I have read in some of your posts here that you sometimes tell customers to try out the wing with just a weight belt first and then order the bolt on weight later if needed.

Thank you for all your help.

I will be ordering as soon as I get your recommendations.

At 5'6" tall you need a medium Plate. 24 lbs of suit buoyancy means the plate should be Stainless Steel.

A medium SS plate and harness is a bout -6 lbs, a reg is -2 and a near empty Worthington HP100 is a bout -3 lbs. Your rig, with an empty tank will provide about 11 lbs of the 24 lbs of ballast you need. You will need another 12 ~ 14 lbs of ballast.

Your rig with a full tank will be about 11 + 8 (weight of the gas) = 19 lbs negative. If you choose to use the 8 lbs weight plates your rig would be about -27 lbs.

A LCD 30 wing is a reasonable choice. 30 > 27, so you can float your rig with a full tank + weight plates, and 30 > 24 so your wing can deal with the unlikely event of a total suit failure.

A LCD 30 is far larger than needed for your warm water diving. A 3mm suit and al 80 can be used with a very small wing, Torus 17 for example, but we have quite a few users that take their LCD 30's or Torus 26's on vacation. You would of course remove the weight plates.

Do you need the weight plates? I can't say with certainty. It's reasonable to buy the BP&W and do a careful weight check, and trim check and then decide.

I like to see cold water divers have a bit of ditchable ballast, and if you need 12-14 total in addition to your plate and reg and tank the 8 lbs weight plates still leave 4-6 in a belt. OTOH, you have a dry suit so redundant buoyancy is available.

A Hogarthian Harness should not be feared. They are different, not difficult. Proper set up and some practice is the key. Adjustment for cold water to warm is pretty easy.

Recap:

Medium SS Plate
LCD 30 wing
Hogathian Harness
8 lbs weights (maybe)

Tobin

 

[Scott M]

Tobin, I don't mean to highjack the thread. I see you do these calculations all the time which is a great service but I am confused a little at how they are done.

In the above example the poster needed 24 lbs. When you do the calculations you work from that figure. Where I am confused is that the poster needed 24 lbs with the HP100 and regulator on so in reality he needed the24lbs and the reg (-2)and HP100(-3) so a total of 29lbs (if the reg and tank are subtracted from weighting requirements). Why is the rig subtracted from the 24 since he had it on when doing his bouyancey check?

Thanks

Never mind, The bouyancy check is done with out the rig.

 

[cool_hardware52]

I am confused.

Yes you are.

The 24 lbs reported were for the diver in undies and dry suit only.

The "goal" is to end the dive with your total ballast, i.e. plate, empty tank, reg, and additional ballast = to the buoyancy of the dry suit.

Tobin

 

[Scott M]

Yes you are.

The 24 lbs reported were for the diver in undies and dry suit only.

The "goal" is to end the dive with your total ballast, i.e. plate, empty tank, reg, and additional ballast = to the buoyancy of the dry suit.

Tobin

Thanks Tobin, I kept reading your calculations but never saw the thread where you explained it was with out the rig.

I am going to have to go out and do this.....then plug in the numbers.

 

[Rand]

Yup, just to confirm, the weight needed to sink me and my drysuit was with the exposure protection and undergarments only, no other gear. Thanks for the help Tobin.