Susna shituation

How things can go wrong in Susna Boof Shower drop. The drop is known to be rather safe to experiment. People have done it with playboats, nose first and tail first etc. Seems though that the left line from the drop can be rather bad- one of our folks hurt the rib due to a stone that was under the left line of the drop. I got stuck in a small but rather efficient eddy since my spraydeck blew off with landing (I landed a bit sideways which also had it's effect on it).
I literally found only one single rock-edge to grab, there literally wasn't anything else. If it wouldn't have been there then I should have swam all the time since the current of the eddy was so strong it always swept me off my feet (the rock slope to stand was super-slippery and rather steep). I could only stand there thanks to this single edge I was holding onto.
3 loops in this foamy and boily eddy was so tiring that I'm quite sure I wouldn't have made it by just swimming. Unless maybe paddle-swimming would have brought be out from there but I doubt it- the boil was strong enough that my body position in the eddy under water was always so messed up I couldn't even get good swimming posture in the water. Suffice to say- trying to swim while there is a danger of getting hit by a boat descending would have been bad idea anyway.
Things to do better next time for all of us:
1) Carry a whistle- just yelling wouldn't have helped in this cave-like place. The waterfall was so loud it would have cancelled out all the attempts to call for help. Whistle though would have probably been heard from above the rock (few people were standing above me).
2) Scout much more even if you're sure that some places should be safe.
3) Safety: Make sure the group has safety set up in places like this. This time all of our folks were rather carefree about the landing zone.
4) Hand signals: No descent before there is an actual green light for it. Currently a boat came a moment later after my landing. If I would have still been swimming under the waterfall then it might have been deadly. Everyone in the group should be sure what's the no-go/stop sign and go-sign for proceeding. In general- handsignals must be known well.
5) If you think sth is wrong then best make sure to quickly check the situation. Might be that it is a matter of seconds to help someone. This time it took 4:45 to help me out after the spraydeck blew off. It could and should have been much faster.
6) Don't be over-confident about anything.
Water level in Susna at that time: 28m3/s (falling)