What good is grapeshot?

[Silly Princess]

Previously I've had good luck with the grapeshot reducing or killing the enemies on board; today however has been a different story. Whatever they've changed, I can't seem to see all or even sometimes one enemy onboard, so I shoot for a while and finally board; it works out ok on the lower ships even if there's a few left, but if I get bad luck and get a large crew I'm done for.

I realize they respawn after a while if you don't board, but that doesn't seem to be the issue today; it's just that I can't see anyone to hit, no lvl's going down etc.