Should I layer a 3mm and shorty?

[bearhere]

Planning a Costa Rica dive in March. Last time I dove Kona I froze with my 3mm. I have a 7mm for cold mountain lakes and Monterey Bay (Brrrrr). I have a new, never been worn 3mm shorty, I always get too cold to try it. I also just bought a Bare 7mm step in hooded vest that I tried once and couldn't get down, Does Michelin woman give you a picture?

I bought "almost good enough" and now own several pieces of gear that I don't wear. I would love to use what I have purchased so....
#1 is it a good idea to put the 3mm shorty over the full 3mm suit? fits OK
#2 thoughts on 7mm hooded vest over the 3mm suit? or is it tropical overkill.
or.... #3 just buy a 5mm and suck it up?

We will be in Northern Costa Rica est. water temp, low 70's.

Thanks in advance and you can be brutally honest.

 

[dumpsterDiver]

a 7mm hooded vest over a full 3mm suit might be perfect for low 70's, depending on the person , cold tolerance etc.

I think I would bring the short 3 mm as well. You might want to wear all three suits if that would fit.