Great thread. While not as intimidating as many of these stories are, my worst case was also my on my OW checkout dives off Key Largo in mid-March. There were four of us in my group getting certified - myself, my daughter, and two sons-in-law. Water temperature was ~68 degF, and I had a brand new (very floaty) 5mm wetsuit. We get out to the dive site (the Benwood if memory serves), and there are 5-6 foot swells - questionable conditions for new divers I think. The boat has about 20 divers, and is completely out of lead by the time we splash. Unfortunately, none of my group has any idea of how much lead we'll need, and all of us are pretty substantially under-weighted, so there we are, bobbing like corks on the surface - up 6 feet, down 6-feet, up 6-feet... you get the idea. One son-in-law starts getting pulled away from the boat by a surface current and freaks out - thinking that he'll get lost at sea - and decides to thumb the dive and heads back for the boat. The rest of us divvy up his lead and finally are able to get beneath the waves - only to be confronted with a pretty good amount of surge. This wouldn't bother me now, but back then we are all trying to fight the surge (bad idea). We do our skills, and swim around looking at the reef/wreck for a little while (I remember seeing a small electric blue eel protruding from a deck plate, and we got to swim for awhile with a sea turtle), then surface to find out the waves are now 6-7 feet. Getting back aboard is "interesting". Lessons learned: 1) know how much lead you really need by testing a new wetsuit FIRST, 2) large swells benefit from a negative entry, 3) don't fight the surge - the fish don't, so why should I?