The Hider of Secret Treasures Commendation in Sea of Thieves requires you to bury valuable treasures for safekeeping. This Commendation has multiple Grades, and you can check your progress by going to your Pirate Log in the menu, selecting Reputation, Bilge Rats, then Buried Treasures. It should be the first Commendation on the first page (top-left corner). Here are some of the best methods for completing Hider of Secret Treasures.
Buying and Burying Merchant Resources
Fortunately for players with lots of Gold, “valuable treasures” include all Crates sold or provided by the Merchant Alliance. If you want to complete this Commendation quickly, buy all of the available Crates under the Browse offers, Resources and Commodities section (10 or 11 Crates total, depending on whether you’re a Pirate Legend) when speaking to the Merchant representative at any Outpost, then bury them on the Outpost.
To bury valuable treasure, place it on the sand with plenty of room, select your Shovel from your Equipment Radial or Inventory, then hold Left Trigger (LT) to dig when the prompt appears while looking at the object you wish to bury. You’ll have to release and hold LT again after each animation plays until the item is completely covered up. Remember that the Merchant won’t let you buy the Resources and Commodities Crates multiple times, and you can’t rebury the same items to get progress toward the Commendation, so exit the server and join another or sail to another Outpost to repeat the process.
Burying Merchant Voyage Items
If you want to spend less money, you can purchase Trade Goods Voyages from the Merchant Alliance that have you deliver various commodities to another NPC. At least one of the goods you’re required to transport is often an animal. The Merchant you purchased the Voyage from will provide you the requisite Crate you need to capture said animal if you speak to them again, and these Crates count toward Hider of Secret Treasures if you bury them.
Therefore, you can purchase a Trade Goods Voyage, vote on it at your ship to start it, collect the Crate(s) from the Merchant, bury them, buy another Trade Goods Voyage, go back to your ship, cancel your previous Voyage, and start the next one to get more Crates. Repeat this until you finish the Commendation.
Reburying Others’ Valuable Treasures
Another way you can complete the Hider of Secret Treasures Commendation, and the way we recommend you do it, if you also want to complete the Seeker of Pirate Plunder Commendation simultaneously for uncovering valuable treasures buried by other pirate crews, is by reburying treasure found via Quest Board maps. You can take five maps per in-game day, and we recommend going for the treasure on islands that are closest to you first.
Access a Quest Board on any Outpost, grab some maps, locate the islands on your Map Table, sail to each, and dig up the treasure there. Once you dig up each piece, rebury it. You can then dig it up again if you wish to take it with you and sell it. This will give you progress toward both Hider of Secret Treasures and Seeker of Pirate Plunder.