This is the plan. I will be in Maui soon and the water temp is about 72-74 degrees. I currently own a 3-2 mil jumpsuit. I know on extended dives that I will need more on my chest. I do not want to spring for a 5mil now so how about putting a 3 or 3-2 shorty underneath? I tried this on land and it seems comfortable besides having to adjust the two back zippers that bush into my back! I also experimented with putting one larger 3 mil over my 3-2 mil and it was ok, but a little restrictive at the knees and elbows. What are your thoughts and experiences. I am trying to keep my options open and frugal.