After reading forums on wetsuits, I like to see if you'd agree that 3 mm shorties would be adequate. We are going to Jamaica after Thanksgiving to get my husband's diving certificate. We'll probably do 1 morning dive & 1 afternoon dive over 4 days. Then we're going to Cayman in Jan. & probably do 1 daily dive over 8 days. Back to Jamaica in Feb for more diving. The last time I dove in Jamaica in Feb, & Cayman in March I got by with a shorty (don't know what mm thickness), but I only dove 1 time per trip because my husband wasn't certified. So with more frequent dives, will a 3 mm shorty still be okay at those locations for our winter months? Is there much difference in the 5 mm vs. 3 mm?