How to layer insulation under wetsuit

[Centrals]

The suit has to be snug fit. If there is a lot of free room under your arm. You will be in trouble no matter how many layers you had put on other parts of your body.
A thick hood is a good idea.
Put on the wet suit for the first dive and see how you feel.
You might have to adjust your weight accordingly with the addition of layers.

---------- Post added January 2nd, 2016 at 05:58 PM ----------

The Thermalution has to be next to the skin. That and the 7mm should be plenty. A hood will help, so if all you have is a hooded vest, that would be between the Thermalution and the 7mm.

I would do the same.

 

[Oldbear]

I dove in New Mexico, Colorado and Alaska waters in the 50s in a rash guard and a 7mm and was just fine.

A wet wet suit by design does not keep you warm. Rather they reduce the rate in which your body looses its core temperature to the surrounding water. They trap a layer of water (hence the term wetsuit) inside and your body heats that water. As long as your wetsuit fits properly it should minimize the amount of water traveling in and out, thus minimize the amount of water your body needs to reheat. The neoprene thickness does provide a barrier between the body heated water on the inside and the environmental water on the outside of the wetsuit.

So insulative layers on the inside of a wetsuit so not do much for you. Your heated vest won't provide extra insulation, but, will provide extra thero heat thus help keep you core temperature loss to a minimum. Just don't sacrifice mobility for too much under your wetsuit.

 

[diversteve]

I'm not sure if you're aware of this or when you're going but El Nino has had a big impact there this year. Solmar V Socorro Dive Reports These quotes are from Dec. 17th-18th 2015.

The dive took place only in the NorthWest side of EL BOILER, our average depth 65ft/19m, water temp 81ºF/26ºC, dolphins were not getting tired.

Today we dove Roca Partida and the conditions were excellent, water temperature of 80f/26C and crystal clear water with 100ft+/30m+ visibility!

My buddy is there now on Rocio - coming back later this week - If he recorded any temperatures I'll post them here.

 

[Dive Right In Scuba.]

This is going to sound like an echo, but I agree with all of those saying you are looking at too much gear. At 72° F, I would probably think first of using a good 5mm suit and maybe a hood--maybe not. for a longer dive, a 7mm suit would be plenty for me, especially with a hood. Add Lavacore, and I would be downright toasty.