I just beat the first boss, sailing back to the west and I am accosted by pirates. This whole sequence is buggy, not sure how I'm supposed to do it. But eventually I kinda fly over their boat and can keep sailing. However, the screen will not move. I can hear the boat get to land, and I can jump out and start walking, but my view is solidly of empty ocean. Tried this like 5 times, can't get it to work properly. Any ideas?

Solved. Apparently you're supposed to run around until they run out of cannonballs. Not sure how I kept managing to fly over their ship but...