Rare has listed the top five rarest achievements in Sea of Thieves, so we sailed off to the land of achievement data to see how these same achievements fare on TrueAchievements…
Sea of Thieves is busy celebrating its fifth anniversary, and looking ahead too, with the devs considering smuggling, griefer protection, and more in its plan for the next five years. As part of the anniversary festivities, Rare shared some interesting stats about the game, including its top five rarest achievements: Voyager of Lost Souls, Merchant Voyager, Merchant Forager, Legendary Hunter of the Sea of Thieves, and Sailor of the Merchant Alliance. These achievements are clearly aimed at veteran pirates, rewarding everything from completing 250 Order of Souls Voyages to receiving the Commendation for sailing 1,000 nautical miles on Merchant Alliance Voyages.
Top five rarest Sea of Thieves achievements as ranked by Rare

Sea of Thieves achievements with the highest TA ratio
We thought it’d be interesting to see what TrueAchievements has to say about Sea of Thieves’ achievements (with the TA ratios and TA scores being correct at the time of writing) — first, we looked at those achievements with the highest TA ratio (we’ve got a handy guide on explaining your TrueAchievement score which goes into detail on the TrueAchievement ratio), and the list immediately changes. Considering Season Nine has just begun, it’s unsurprising to see its achievements shoot to the top with the highest TA ratios: the Favour the Bold achievement for handing in 30 Chests of Fortune currently has a ridiculous TA ratio of 107.49 with only 43 tracked gamers, while A Favour for the Flame (which asks you to hand in 30 Reaper’s Chests or Reaper’s Bounties) follows behind with a TA ratio of 67.51 and 109 tracked gamers, then Hot-Headed (where you need to use a Skull of Destiny to begin three Fort of the Damned events) with 33.15 and 455 tracked gamers.
Excluding Season Nine, the next achievements with the highest TA ratio are from DLC and updates: first is Veil Seeker which currently has 35.56, from the Legend of the Veil update, with 15% of its 395 tracked gamers having unlocked it. Considering some TA ratios can be considered high without even breaking double figures, Veil Seeker’s 35.56 is nuts. Then Season Eight’s Ritual of the Flame achievement follows with a TA ratio of just over 29, with 4% of its 584 tracked gamers having unlocked it. Then a few of the achievements on Rare’s list of the rarest achievements show up, with the Voyager of Lost Souls and Merchant Voyager achievements having TA ratios of 23.91 and 23.01, and Legendary Hunter of the Sea of Thieves having a TA ratio of 22.44.
Sea of Thieves achievements with the highest TA score
Multiplying the Gamerscore value by the TA ratio gives us our TA score. Again excluding Season Nine (which offers formidable TA scores of between 146 and 5,374), the achievement with the highest TA score would be Season Five’s Beholder of Buried Treasures with 1,736 TA score — except this achievement is still listed as buggy. Then Season Four’s Legend of the Sunken Kingdom achievement rears its head with a TA score of 1,536, followed by Season Eight’s Ritual of the Flame with over 1,450, and the Blessing of Athena’s Fortune achievement, again from Season Eight, with a TA score of around 1,430. Up next is the Legendary Hunter of the Sea of Thieves achievement with a TA score of around 1,120, and then Season Eight’s A Sunken Century achievement with around 1,110.
All-in-all, the only achievements from the base game which feature in here are on Rare’s list of the rarest achievements: Voyager of Lost Souls, Merchant Voyager, Merchant Forager, and Sailor of the Merchant Alliance. Aside from that, Season Eight has three achievements listed on here, with the rest scattered across other DLC.
What have been your most memorable Sea of Thieves achievements? Let us know in the comments!