Rule 'o Thumb re: Undergarment Weight Needs

[Birmbear]

So...I'm off to the pool tomorrow with my new White's Fusion to get my dry suit cert. I'm thinking that I don't want to dive with my bunny suit (Pinnacle undergarment) or Whites Mark III under it. Both would make we way too hot for a pool dive. The thing is, the next dive is into the Puget Sound, and I want to make sure I have enough weight then to do more than just snorkle.

Clearly, I either have to estimate the additional weight I'll need wearing the bunny suit or Mark III in the ocean, or I'll have to actually try them in the pool and do an actual weight check.

So....if I go with the estimation method, what's the rule 'o thumb? My bunny suit is a XXL. Given that...and given that I'll be already carryihng a certain amount of weight to counteract my drysuit, bcd, tank, etc....how much additional weight do I need to offset the undergarment's buoyancy?

Any ideas?????

Scratching my chin,
__Ric

 

[RJP]

A + B = C: solve

Too many variables...

 

[Jang]

Don't bother with the undergarments on the pool dive. You'll quickly overheat.

You can get an estimate of the weight you need if you wear everything you'd normally dive with in a pool, then need to account for fresh to salt water...OR, do a proper weight check when you go diving in the ocean. You're profile location is the Pacific NW, so you should be pretty close to the ocean for a little trial dip in the water.

Yes, you'll have lots of other weight with all of your gear, but remember Archimedes principle...the weight that you are trying to offset is based on the volume of water displaced. A drysuit traps lots of air and displaces even more water. Unless you have backplate and/or steel tanks, you're going to need more weight than you think, especially first time out.

Then again, what do I know, I still a noobie.

 

[Rick Inman]

I have the MKIII and it takes a bunch 'o weight. But like RJP said, all you can do is guess until you hit the water. That's why, for a weighting dive I like to start out with some kind of pocket on my weight belt, so before I start the dive I can easily add and remove weight and test. Then I do it again at the end of the dive.

In fact, I figured those soft weights I left on shore at Three Tree (5 years ago) would be safe until after the dive, but someone took 'em.

 

[elan]

The solution is a s simple as that. Get in the water and do the proper weight check. You can do it even in the pool. Despite of the popular belief you will NOT overheat in the pool. I dove at least 5 times in the 80 degrees pool in full winter gear and did not overheat. Unless you start going for the Olympic record you will be fine. Your undergarments just keep your body temperature the way it is. You will sweat much more though, your undergarments are designed to suck in all the sweat. Just drink enough water. As an alternative go to the nearest quarry or the lake or whatever calm water mass you have nearby and do the proper weight check.

If you do the proper weight check you will save your buddies the next dive.

You know in Asia they wear thick robes in 50C (~130F) air temperature for the sake of protecting from the sun and heat. They do not overheat.

 

[Rick Inman]

You can do it even in the pool.

Remember, too, that the pool is fresh and Puget Sound is salt and you'll have to adjust for that.

 

[elan]

Yes Rick you are correct. Diving in the lakes I"m so used to the convenience of the pool weight check with no adjustments necessary for the transition. Still I guess the transition fresh - salt is more predictable than transition no undies-undies