A recent blog post states that the beta will run for short period of five days from January 24 at 4 a.m. PT,7 a.m. ET,12 p.m. UK,10 p.m. AEST to January 29 at 12 a.m. PT,3 a.m. ET, 8 a.m. UK, 6 p.m. AEST.
If you were someone who had signed up for the Sea of Thieves Insider Programme before December 1 or had preordered the game, you will have automatic access to the beta. Rare has also promised that the closed beta will be “a true taste of what Sea of Thieves has to offer,” however it won’t be the full experience.
Players will also be able to freely stream the game, take screenshots, and create and share gameplay videos/clips.