One of the many commendations you can complete as you explore the Sunken Kingdom is the Seeker of the Sea commendation.
To complete this commendation, you must sell 30 Breath of the Sea treasures to any Trading Company.
While 30 doesn’t sound like a very high amount, you can only find this treasure in the Sunken Kingdom and only while you have a specific quest active.
What is the Breath of the Sea
The Breath of the Sea is a mysterious treasure that contains the same power held inside the Mermaid and Siren Gems. The Breath of the Sea looks like a glass bottle holding blue, green, or red liquid.
There are three different rarities, each offering greater rewards: Sapphire, Emerald, and Ruby.
How to find Breath of the Sea treasure
You can only find Breath of the Sea treasure during an active Coral Message in a Bottle Quest.
The quest will direct you to a Siren Shrine or Treasury that holds the Breath of the Sea. To successfully collect one, you will need to solve puzzles and fight off sharks, Ocean Crawlers, and Sirens to reach the Coral Plinth that holds the treasure.
Once in your possession, you can sell the Breath of the Sea to any Trading Company for a generous reward.
How to start a Coral Message in a Bottle Quest
To start the quest, you must first find a Coral Message in a Bottle. They will appear randomly on beaches of islands throughout the Sea of Thieves. As you sail around, jump off on islands you pass by, and scour the beaches for the Coral Message in a Bottle.
You can also find them randomly in shipwrecks or Barrels of Plenty!
Once you pick one up, the quest will begin. You can view the quest it gives you from your Quest Radial.