7mm vs. 3mm - how much warmer?

[Li'l38]

Can anyone tell me how much warmer I'd be if I break down and buy a 7mm wetsuit? I have a 3mm and it's great for temps above 76 degrees. However, when diving the springs (72 degrees), I can't stay in the water much more than 30 minutes. Would it do any good to wear additional wetsuit or shorty over the top of my 3mm? Or something else under it? (Not sure if that's effective) Looks like I'll be diving the springs enough to have a warmer wetsuit. Don't want to spend the bucks if I won't be much warmer though. Maybe something else I can do? I know wearing a lycra skin underneath does NOTHING to help. Actually, I think it may have made it worse. I'm thinking a 7mm would be good for deep diving too. Drysuit is not an option right now. I already have a small fortune invested (who doesn't?) I know, it's an expensive sport. Help me spend my money wisely

 

[Ron Brandt]

A friend of mine can do a 45 minute dive in 38 degree water with a 7mm wetsuit.

I use 3 mm in a 78 degree pool for 1 hour. While in Coz I use a 5mm for 2 one hour dives.

When the water drops below 68 I use a drysuit.

Ron

 

[dirthead]

I wear a 2.5mm shortie over the top of my 3mm full suit in water temps between 65°-75°. That works pretty well since it gives you more core coverage. As long as I am moving around I'm ok. For colder diving in waters from 50°-65° I wear a 7mm suit and am very comfortable. You might also try a hood. You lose a lot of your body heat through your head. You might be surprised how much a hood will help when wearing just a 3mm suit.

 

[Land Locked]

If your only going to be diving in 70+ degree water you can do what I do.
I use a 3mil shorty as a core warmer and I also wear a 3mil cap/hood.
7mil would be over kill in those kind of temps, I've heard many a diver say
they were overheated in 72 degree water!

 

[abitton]

If your only going to be diving in 70+ degree water you can do what I do.
I use a 3mil shorty as a core warmer and I also wear a 3mil cap/hood.
7mil would be over kill in those kind of temps, I've heard many a diver say
they were overheated in 72 degree water!

Yup. Made me sick.


Alex

 

[spectrum]

In 70 something degree water a 7mm should probably be uncomfortably hot, I know it is for me.

Adding a shorty of even beter a hooded vest preferably worn under will do wonders for you overall. I find that if my core is truly warm then my limbs also stay more comfortable.

In any event make sure to have a hood or at least a beanie. Covering the head is another great help.

If you have other deep/cooler intentions a 5mm may make some sense but how cold and deep is the deep you're considering.

I have come to accept that one suit does not do it all if your diving has variety. The 40 something ocean and the 76 degree pond cannot be comfortably and safely dived in the same protection.

Pete

 

[PerroneFord]

I get cold pretty easily. That said I bought a 2 piece Henderson set. A 5mm step in with long sleeves. And a 7mm farmer bottom. In the warm water, I essentially have a long sleeve shorty. Enough skin is exposed on the legs to keep things nice, an I can always unzip the top a bit to allow some flushnig. When braving colder water, that 7mm bottom will come out. A total of 12mm over the torso will do nicely as it gets colder.

Problem is that my buoyancy is going to be HELL to deal with. One thing I didn't see anyone mention here is depth. As you go deeper, that wetsuit is going to compress and lose thermal properties pretty quickly. If you're tooking around at 30ft like I will be, you should be golden. If you dip down near recreational limits in colder water, you may start wishing for a drysuit.

One HUGE mistake I made years ago was not fully understanding the power of a hood. You lose a TON of heat through your head, I think estimates are like 35% or more. I will buy 2. One 3mm and one 7mm for varying conditions. I don't think I will dive again without a hood, even in the tropics. Some people hate them. I rather like having my head covered. Maybe I'm just chicken something will swim into my ears!

 

[Scubakevdm]

I am also from Florida, and dive the winter through. I switch to my 7mm when the water dips below 80 until it gets down below 71, then I wear a drysuit. I typically spend about two hours back to back underwater in rapid succession almost every day. I don't move a whole lot when I'm down there 'cause I mostly drift dive. Typically my dives are in the 65-115' range. I own Everflex wetsuits and am extremely happy with them. There's a whole other thread on that somewhere... just search Everflex if you're interested.

 

[ScubaSarus]

At 72 thats more 5mm territory. I was overheating big time at 73 in a 7mm trying to get cool water into the suit.

 

[The Kraken]

The only way for you to know, exactly, is to try it.

Each one of us has differing thermal characteristics and, as such, each one of us requires different levels of thermal protection.

The matter is extremely subjective.

the K