To Musicalklutz:
Be sure you go to post #7, counting over from the broken part of the fence. Back up only 4 steps. Start with the Stink Pot and target the group. I held down the mouse button trigger until the indicator was about 60-65%, then let go.
I noticed that if I had to share the location with any other pirate, regardless of whether they were using nades or staff, the soldiers would make it through the fence. Be sure you go to a quiet server, and are there alone, or only with one other pirate who is there to help you tp back after resupplying yourself with ammo, so you don't have to sail. Try to avoid sending any more long volleys to bring over more of the group. The more the group splits up the harder it is to keep them on the right side of the fence.
Just my observations. Hope it helps!
Andrea Shorecastle/Darkcastle