OK, I have to chime in here and ask a question, am I the only one who dives with a bcd that doesn't cinch it down like I'm racing a car or getting ready for a plane crash. I snug the bcd down on the surface and if you look at myself or others underwater you will find most of the time if you look at their bcd from underneath them, there is a bunch of room between body and bcd. I have noticed over the last two years looking at video I have shot that many divers don't cinch their bcd's tight especially the waist area, as you dive you shrink but the bcd stays the same so there is usually about a 4 inch gap I've noticed between body and bcd. I see no need to have this thing strapped to me like its going to float away. Be comfortable, it won't leave you. I roll over and swim upside down and every other angle and never have had an issue with any of my different bcd's. If you have trouble with it riding up then yes a crotch strap will alleviate this. I am a firm believer in buy the largest size bcd that will fit you when you snug it down to minimum specs. This will allow you to grow or use a heavier suit.