Here is the full list of all 16 Blazing Sails: Pirate Battle Royale achievements.
Customize your ship.
Customize your pirate.
Gather your crew for an adventure.
Welcome aboard, sailor!
Claim your first victory upon the seas.
Find and open a treasure chest.
You best find some sea turtles, mate.
Discover the Trident of Poseidon.
Discover the Tropical Paradise.
Discover the Temple.
Avenge your own death.
Claim a life while your ship is sinking.
Join two different crews in the same game.
Win a match while having the highest score.
Kill 2 pirates with a single cannon shot.
Now you walk like a duck, so talk like a duck.