I have been in a 6m Osprey with 11 divers and kit onboard after the second boat broke down ( 8 normally the max). We were in a flat calm in sheltered water. It was tight enough but doable, wouldn't like to think what another three folk and sets of kit would have been like.
My 5.3m is rated for 6 divers and kit or 9 folk. That is possible but I generally have a max of 4 divers and kit or 6 folk. Any more than that and the boat is just a bit too crowded for comfort.
They must have been standing on top of each other to get 14 sets of kit and divers in the boat. What were they thinking about?