A late ship usually means trouble from pirates, weather, mutiny or all three.
Find out why the Pointe-à-Pitre Musketeers' shipment of muskets is late! Escort the delayed ship to port on your own. Sea battle vs 7 level 48 to 50 ships. Once the delayed ship gets damaged you will need to board it and rescue the crew. Killing 12 level-50 pirate boarders. Once done, talk to the captain to be transported to the beach for more avcom vs level-50 NPCs. Protect the captain and make it to the marked battery for a final showdown.