Are inside or outside extra neoprene layers warmer?

[cephalopod2]

I am a huge fan of my 5/7 hooded vest - on to my third one and wore it 90% of the time inside my (well-worn) 7 mm when diving anything below 82.

Alas my 7 mm up and died this summer and in buying my replacement suit, there was a hooded "over vest" for sale - shorty arms and legs with a hood attached. Since it was a great price, made to fit the steamer, and my current hooded vest will eventually wear out, I thought I would give it a try.

Now I am wondering about the effectiveness of inner vs outer extra layers. All other things being equal - i.e. a primary suit that fits well and an extra layer of comparable thickness, fit and quality - do outer or inner hooded layers keep you warmer?

Thanks for your thoughts.

 

[diverjen]

I am also one of those coldies who is shivering in a 3 full in 81F water with a hood and vest under. Love to hear the answers!

 

[Rich Keller]

Having extra thickness will help keep you warmer but having it in multiple layers also cuts down the exchange of warm water from inside the suit to the outside. Same basic idea as a semi dry wetsuit, water will get in but it has a much harder time getting out. I do not know if having a hooded vest worn on the inside or the outside will make much difference.