I was never one for the Euro-style weenie-shorts, or any other specialized shorts. I did a few thousand dives with trusty boardshorts under my suits. Sure, they're a little bunchy, but if you stuff them down as you're pulling the suit up to your waist, and don't let them bunch up on you like a diaper, they're fine. I had lots of long days this way, and my personal record was 14 hours straight in shorts/suit (at least up to the waist), and never had any issues with any "groinal disturbances".