Add a vest over or under full suit?

[Kryssa]

I’m trying to get a bit more warmth out of my 3mm suit when I dive the cenotes around PDC next month. I usually wear a 5mm full suit on these dives but I’ve lost weight and only have a 3mm in my current size.

If I buy a 3mm vest, would I wear it over or under the 3mm full suit for the most warmth?

Thanks.

 

[rongoodman]

I’d make it a hooded vest underneath if it will fit.

 

[scubadada]

Absolutely under

 

[Divin'Papaw]

Vest underneath. 100%. Ideally hooded.

 

[MB NZ]

Agree with the comments above. If you can stomach a little lube, open cell with be warmer and more comfortable.

 

[Kryssa]

It won't be hooded because I have a lot of hair and HATE wearing a hood. (The hood in my profile photo is a drysuit hood so the hair gets to stick out the bottom in a braid.)

Whatever warmth I get, I get, even if its not ideal - but I will wear it underneath the full suit. I will also bring a beanie. Thanks!

 

[Still Kicking]

It absolutely makes no practical difference in my experience (30 years+ diving with hooded vests).

If the fullsuit is snug, put the vest on the top. If the suit is a little loose in the chest and the neck, put the vest underneath.

Effectiveness of the seal keeping water from flowing in and out and the combined thickness of neoprene is what matters for insulation, not which layer is on top of another.

However, as MB NZ points out, if the vest or suit is open cell neoprene that material will keep you warmer if it's next to your skin for more a effective seal.

 

[Eric Sedletzky]

I used to put the vest underneath and I thought that’s how it always had to be done.
Recently I bought a full suit that has a thick spine pad and skin seals for the neck area. If I put the vest underneath then these features are useless, so I decided to try it with the vest on top and I’m warmer. I can also take off the vest during a surface interval and still have the full suit on and not need to pull the hood down around my neck, so it’s actually working out better with the vest on top.

 

[BoltSnap]

Under the 3mm suit!

 

[Drip Dry]

I wear my 2/5 mm hooded vest over of my 7 mm wetsuit. I originally tried wearing it under my wetsuit but found that I'd sometimes get leakage between the vest and the wetsuit at the back of my neck when I bent my head forward. Hate that trickle of cold water down my spine. Wearing the hooded vest over the wetsuit eliminates this leakage.

... I can also take off the vest during a surface interval and still have the full suit on and not need to pull the hood down around my neck, ...

Well noted, this is another benefit of wearing the hooded vest over the wetsuit. My previous wetsuit had an attached hood, which I liked while underwater (no leaks) but didn't like during a surface interval, pulled down the hood felt constricting around my neck.