At the top you say that the solemn ship sailed into view, but the view of who? (whom) The men on the ship can see what they're standing on and from there you don't talk about the people on shore.
From there a few sentences are a bit too "here's the facts", they could use a bit more integration into the narrative. For instance you could say "Through a darkened evening a solemn ship crewed by ghastly and glum pirates slowly sailed into a lonely bay, searching for an appropriate location to cache their recently acquired plunder" and continue from there.
You're making it clear that the crew isn't behind the captain in the next paragraph, but I don't think they're in the position yet to be making group decisions yet. Have the moves be entirely the captain's plan, but have the men question it amongst themselves when he isn't around.
For the next paragraph just from my view of pirates, you might feel differently, but I don't think they would attempt a fight they don't have a large advantage in. Say that they had been receiving information about this envoy and it had been wrong, the troops were more numerous than they were able to confirm before the initial attack.
There's a problem of terms in this next paragraph. The order is actually "Weigh anchor", but weigh anchor means to raise the anchor. It's also quite a pain in the patoot to get a full sized ship loaded with loot off the shore once you get it up there. For a quick getaway situation like this, are you sure that's the best plan? You might want to go with the anchor in the harbor and use rowboats to get the men ashore.
The last thing is the mention of Akavir. They've been pirating around the western half of the continent all this time, but they every now and then sail to the other side of the known world? It seems out of character for pirates.