Sea of Thieves Patch Notes: Season 21
Sea of Thieves 3.9.0 adds the permanent Parley Pennant and Custom Seas Layouts. The full Season 21 changelog; every update, active or vaulted.
When is the next update?
Sea of Thieves rolls to its next season around December 29, 2026.
3.9.0: September 17, 20264 changes
The Sea of Thieves 3.9.0 patch notes mark the Season 21 launch, adding the permanent Parley Pennant crew-communication tool, saveable Custom Seas Layouts, and new ship-visibility switches. Track the live Sea of Thieves season countdown to Season 21’s close.
TL;DR, 4 changes: 0 buffs, 1 nerf. Biggest addition: the permanent Parley Pennant, unlocked after speaking with three crews via its Proficiency Sails. Biggest nerf: ‘Dive To’ travel is pulled from Voyages, Tall Tales, and Raid Voyages as a time-limited experiment. Meta impact: crews now sail to most quest locations instead of teleporting, while Custom Seas hosts gain persistent Layouts and finer ship-visibility controls.
Mechanics
- Parley Pennant, a new permanent Flag Box option signaling a crew wants to talk; unlocks the Parley Proficiency Sails after speaking with three other crews active
- Custom Seas Layouts, creators can save item placements as a Layout and reload the full setup later, up to 30 per Location active
- Custom Seas ship visibility, new Switches let hosts show ships as anonymous markers or fully identified by type and crew iconography active
- ‘Dive To’, removed from the Quest Table for Voyages, Tall Tales, and Raid Voyages; crews must sail to their location instead (Hourglass and Last Ship Standing still allow it) nerf
All Sea of Thieves patches
| Version | Date | Season | What changed |
|---|---|---|---|
| 3.9.0 | September 17, 2026 | Season 21 | , 4 changes: 0 buffs, 1 nerf. Biggest addition: the permanent Parley Pennant, unlocked after speaking with three crews via its Proficiency … |
| 3.8.1 | Jul 23, 2026 | Season 20: Custom Seas | 5 changes: 0 buffs, 1 nerf. Biggest addition: the Pirate Practice preset for drilling World Events and naval combat. Biggest nerf: Bone Call… |