Undergarment buoyancy

[ZeroG]

What is the best low buoyancy drysuit undergarment?

My new Santi BZ400 is plenty warm, but I need an extra 14lbs to get under. I tested it in pool with all equipment being exactly the same, and a Bare SB took 24lbs vs the Santi BZ400 at 38lbs.

I can give up some warmth, and upgrade other gear items, but probably need better than the Bare SB in 50F water.

Any suggestions for low buoyancy and warm? I realize I'm asking a lot, but my Scuba Board buddies have never let me down yet.

 

[JohnnyC]

I seem to remember my Whites Thermal Fusion deal not requiring a ton of weight. It's super warm too. Obviously it's also anecdotal.

 

[elgoog]

I added a Santi BZ200 vest - noticeable difference in warmth and I didn't need to add any extra weight.

Have you dived around here in the Bare SB? If you're doing single tank dives that are under an hour and you can get warm during the SI, you may find it works fine. I pretty much only dive doubles at home and my dives are generally in the 75-90min range; I need the XM450 for that and have started adding the BZ200 vest if I'm on my DPV and not swimming much.

 

[Rechno]

14 lbs sounds really much. When I change from a light undergarment to the BZ400x I have to add approximately 2-3 kg.

 

[Erik Forsberg]

This is a very good and relevant question. I also need something ridiculous like 6kg extra in my undergarment and I would also like to have something less buoyant.

 

[Storker]

This is a very good and relevant question. I also need something ridiculous like 6kg extra in my undergarment and I would also like to have something less buoyant.

Problem is, insulation is provided by air. And air is buoyant. Unless you buy an electrically heated undergarment, every W/m2 you gain is paid by the amount of lead on your belt.

 

[ZeroG]

I added a Santi BZ200 vest - noticeable difference in warmth and I didn't need to add any extra weight.

Have you dived around here in the Bare SB? If you're doing single tank dives that are under an hour and you can get warm during the SI, you may find it works fine. I pretty much only dive doubles at home and my dives are generally in the 75-90min range; I need the XM450 for that and have started adding the BZ200 vest if I'm on my DPV and not swimming much.

I have tried the SB in the ocean, it was OK but I would like a bit warmer.

Without biasing my Scuba Board buddies, I was kinda looking for recommendations like add a base layer to SB. Right now I'm looking at xerotherm and Bare cellulient and the 'magic properties' they have to keep you warm. Anyone think these work well or can recommend something else.

I'm also open to any undergarment (or combination) that answers my original question, warmth with low buoyancy.

 

[ZeroG]

Problem is, insulation is provided by air. And air is buoyant. Unless you buy an electrically heated undergarment, every W/m2 you gain is paid by the amount of lead on your belt.

That's about what I learned so far. More air (thicker) = warmer = more buoyancy = more lead.

Exception is there appears to be consensus that adding a wicking base layer adds warmth without much if any buoyancy. How much warmth is up for debate.

 

[elgoog]

I was kinda looking for recommendations like add a base layer to SB.

Understood. The BZ200 vest recommendation still stands for that as you wear with your existing Bare SB. I noticed on most sites you can only buy the heated version of it now - not sure if it's discontinued or what (??) Either way, a similar vest will give you extra warmth in your core and they are not as expensive a full body suit.

What base layer are you wearing now? I wear SmartWool heavy weight base layer always with whatever drysuit undies. That makes a noticeable difference in warmth as well without needing any weight compensation.

 

[Storker]

There appears to be consensus that adding a wicking base layer adds warmth without much if any buoyancy. How much warmth is up for debate.

A good wicking layer is worth its weight in gold. Or perhaps platinum. If you want a full dissertation, ask me about my opinion about wool wicking layer garments. Then sit back and enjoy the ride. It'll take some time...