Neoprene disadvantages - or not?

[cod3r]

This is probably a silly question but I'll ask anyway

It's common knowledge that a neoprene drysuit's disadvantage over membrane is that neoprene compresses with depth. As I understand it this creates two problems:

1) Loss of buoyancy with depth
2) Loss of insulation

But I can't understand either of them

My reasoning is, don't membrane suits also suffer loss of buoyancy due to the air contained in the suit? It can be compensated by adding air. In fact, I imagine the loss of buoyancy in the neoprene will be small compared to that of the air layer. Is it even significant?

Regarding loss of insulation, well fair enough there wil be some. But won't undersuit choice be relevant to the anticipated depth (ie, add an extra layer). Also, a neoprene drysuit will be compressed at most down to "crushed neoprene", which will still provide significant insulation.

I know I'm missing something (the plot?!) but what!!

Also, why is a neoprene suit not DIR (due to the above reasons undoubtedly)?

thx

cod3r

[Al_Star]

Hi Cod3r

The main issue with Neoprene (from a DIR viewpoint) is the change in buoyancy. As you descend the bubbles in the neoprene get compressed which means the suit is less buoyant at depth than at the surface. This means you need a lot of lead to sink at the start of the dive but once at depth you are then overweighted.

The reduction in bubbles also mean the suit provides less insulation as you go deeper.

You can avoid this with a compressed neoprene where all the bubbles are already small. 03 and DUI do suits like that - you get the extra warmth of Neoprene but don't have the change in buoyancy characteristics.

I've got a DUI CF200 at the mo having had a trimlam in the past and with the same undersuit I find it takes longer for me to get cold in the DUI.

Cheers
Al

[Rick Huggins]

Originally Posted by Al_Star

Hi Cod3r

The main issue with Neoprene (from a DIR viewpoint) is the change in buoyancy. As you descend the bubbles in the neoprene get compressed which means the suit is less buoyant at depth than at the surface. This means you need a lot of lead to sink at the start of the dive but once at depth you are then overweighted.

The reduction in bubbles also mean the suit provides less insulation as you go deeper.

You can avoid this with a compressed neoprene where all the bubbles are already small. 03 and DUI do suits like that - you get the extra warmth of Neoprene but don't have the change in buoyancy characteristics.

I've got a DUI CF200 at the mo having had a trimlam in the past and with the same undersuit I find it takes longer for me to get cold in the DUI.

Cheers
Al

Coz your too busy posing to get cold now

[Mark Chase]

I have a 5mm neo 03 suit its the only neo I have ever had so I cant comment on others. The additional buoyancy issue on this suit is 0. I used 4kg with a Membrane suit I used 4 KG with the Neo suit. This is mainly down to tight fitting of the suit. I have little or no air in the suit on the surface so I can get down easily. I THINK the membrane used to have trapped air in it so it was just as hard to get down. This is demonstrated by the fact I never have to do the squat to vent air from the Neo before a dive and I never get the inflated shoulders in the neo when I jump in as I did on the membrane.

If there’s a loss of buoyancy issue at depth I never noticed it. Obviously the bubbles in the Neoprene get compressed so the suit becomes less buoyant but the difference is pretty negligible on a 5mm suit.

Membranes are much lighter and a lot easier to get on and off, dry out, pack but Neo is IMHO MUCH warmer on the dive and there is noticeably much greater thermal protection in the event of a suit leek. Loss of thermal protection or not at depth a Membrane has none at least a Neo has some. The 2mm hyper compressed resin injected suits like the DUI and 03 Ti have no air in them to compress but users claim that they are still warmer than membrane suits?

I wouldn’t go back to membrane for UK diving but I want one for travel. My Neo is 7.5Kg and that swallows a lot of the baggage allowance

ATB

Mark Chase

[beanie]

Originally Posted by Mark Chase

The 2mm hyper compressed resin injected suits like the DUI and 03 Ti have no air in them to compress but users claim that they are still warmer than membrane suits?

yep well mine is

iIwas diving with 4th element and weasel extreme under trilam
now 4th element and othree PBB under O3 2.1 RI and def warmer that fact that it fits may well have a lot to do with it though.

but neoprean seals are warmer though - that does makes sense

[Al_Star]

Originally Posted by Frogman

Coz your too busy posing to get cold now

Lol - I was still getting cold it just took longer. I've been pleasantly suprised how much warmer neo is.

I really need to sort out my undersuit though. 100 gram thinsulate with 4th Element base layer was interesting for 70 odd minutes in 6 degrees!

I'm tempted to go for the Polar Bears undersuit. I did wonder if they were going to be at the Dive show but couldn't see them on the list of exhibitors.

[berticus]

Hey, I've been reading this post and it sounds like you're suggesting wearing an undersuit under a compressed neo drysuit. Why? I thought the idea of compressed neo was to remove the need for an undersuit. I can see why you might want to wear some wicking thermals, but not the full-monty undersuit.

I've only used a membrane so far, and the only benefit I could see in swapping to compressed neo is that there's no need for the undersuit (oh, and they look cool too )

[Al_Star]

Originally Posted by berticus

Hey, I've been reading this post and it sounds like you're suggesting wearing an undersuit under a compressed neo drysuit. Why? I thought the idea of compressed neo was to remove the need for an undersuit. I can see why you might want to wear some wicking thermals, but not the full-monty undersuit.

I've only used a membrane so far, and the only benefit I could see in swapping to compressed neo is that there's no need for the undersuit (oh, and they look cool too )

Hi Berticus,

In this temperature I find the undersuit is still required. I'm guessing that the others who posted do as well. The neoprene is better but not that good.


Cheers
Al

[berticus]

Thanks Al, I'll bear that in mind when I'm buying my drysuit at LIDS

[Allan Carr]

Originally Posted by berticus

Hey, I've been reading this post and it sounds like you're suggesting wearing an undersuit under a compressed neo drysuit. Why? I thought the idea of compressed neo was to remove the need for an undersuit. I can see why you might want to wear some wicking thermals, but not the full-monty undersuit.

I've only used a membrane so far, and the only benefit I could see in swapping to compressed neo is that there's no need for the undersuit (oh, and they look cool too )

Compressed Neoprene is also extremely tough - although some of the newer and more expensive membrane suits are almost as strong, and I haven't seen anything like the leak problems with neoprene that I have with membrane suits.

While neoprene is warmer than a membrane, I still wouldn't like to dive without an undersuit at any time of the year although in summer, I only use a thin one which makes it easy to slide on and off.