After being there for the first and third event (althoug PvE) I agree with some voices here saying, that things should be stretched out a little bit. Maybe the event could take place on a bigger area, not about one quadrant but maybe about four. In these quadrants over the time of a few hours there will be ships spawning regularely, floating up from the depths of the sea like driftwood. Give more people more reason to stay there, raise their chances to get some plunder while looking around a little bit.
For more PvP though (and even for PvE with AI ships) maybe it would be better to put the wrecks inside an instance. Make it like an event marker where ships can enter all the time and try to reach a chest or wreck in the water. Give them a one minute countdown to plunder that wreck - then close the instance. Let people run and fight for some treasure, give people reason to screen their friends while they are loading the chests inside their holds. But let these "events" pop up for some hours in roughly the same big area, so give more people chances to find their luck.