I was kindly invited to a be an underwater photographer for AIDA competition at Lopar (Island of Rab), Croatia. I gladly accepted because it was first time I had a chance to shoot apnea divers.
Divers were competing in three Aida disciplines: free immersion, constant weight (with fins) and constant weight without fins. First discipline was on the first day, the second and third on the second day. What amazed me was the timing of the dives. All the divers are given in advance all exactly the time of their dive and they were very strict about it. Around 10 minutes before their dive they had to relax/prepare for their dive. They only get one chance so they obviously took it seriously. Couple of minutes before their dive time they were literally towed by another (safety) diver to the pontoon with the judges and the rope. At exactly 0:00 they had to dive.
I was a bit impressed how fast those divers go down and up. That presented a bit of a problem though. But this problem wasn't the only one. The other problem was that when shooting the diver from below you have excess of light coming from the surface, and when shooting from above there was substantially less light because the sea isn't very bright. You can see the problem on the next image.
As there was such a big difference in lightning it was impossible to adjust the camera to shoot divers passing by (the first problem). I figured at the end of first day to adjust the camera to P (also known as automatic mode). The results were okay, but I had to manually compensate for like -2 stops. That way I shot pretty much all the pictures the next day. I couldn't adjust the camera just for shooting from above and shoot only from above and vice versa because every diver was separated by 10 minutes. So I would only get a handful of photos to play with later which wasn't my intention. I wanted to have as much photos as possible at the end to see what photos were good (and why) and which ones were bad (and why).
So in the end I did some ok photos as you can check out at photo.adriasub.com.