Has anyone tried both merino wool and the synthetic base layers under there drysuit

They’re not merino sweatpants. Merino wool long underwear.

 

Yeah, I get that they're not sweatpants. That's why I want them - for the snugger fit. And nothing over them, correct?

 

Correct.

 

Excellent. Thanks

 

alright, so I am a textile engineer and this is in my wheelhouse and I have done a lot of work with wool in my career

Everything that we do as engineers is to attempt to replicate nature. Literally everything we do. Nylon was invented to mimic wool, polyester to mimic silkworm silk, kevlar to mimic spider silk, buildings, bridges, everything. We can't beat it.
Wool is no different. We can't make a fiber that felts, we can't make one that is naturally exothermic, naturally antimicrobial, etc. You can't beat natural wool for this stuff, so don't try.

 

I just ordered wool replacements

 

I've been thinking of

This!!!! I always had cold feet and hands untill I bought merino mountaineering socks ( the red Sole smartwool ones) and light Merino gloves ( don't recall the brand) that are worn as a base layer under waterproof gloves. It's gotten me so happy and warm in sub 10 C water that i've been thinking of throwing away the idea of scuba undergarments completely and just go for a full Merino kit (vest + pants). It's also alot cheaper than buying a Santi 400...

 

I use a synthetic silicone koflin undersuit (a super cheap one), I think it was 15$ new, and under that i either wear a merino shirt/baselayer or a 150g polar microfleece.

Never had any problem with being cold, but then again I can stand the cold. Most important thing for me.are the socks, and there I use a fishing socks for rubber boots, and if it's really cold, I use a fleece oversock.

So wool is king, but I don't diss the synthetics

 

I buy merino and cashmere sweaters from goodwill for like $8, sometimes 5. I made a pair of pant from an old pair. Not hard to do. I love it