Until now, whenever Sea of Thieves has been shown off, we've only seen it in action with crews of co-op players numbering at least four. While that is the core experience that Rare has designed the game around, they've been incorporating player feedback and have revealed smaller vessels that players can use to sail the game's shared world either on their own or with one other player.
The feature was revealed in the latest episode of Inn-Side Story, the on-going video series in which Rare's developers talk about some of the behind-the-scenes decision making with the game. Check it out:
One of Rare's most prominent design pillars with the game is removing as many barriers to entry as possible, which they emphasize in the video. Playing the game without a microphone, and now even with other people is a possibility as the developers try to account for every possible contingency. Another part of this strategy is how they've handled the technical side of things in wanting the game to be Crossplay compatible. Another contingency that Rare is preparing for is the full range of PC specs that gamers have at their disposal.
The point is that Rare wants as many different people to play Sea of Thieves as possible, and by removing boundaries such pathways for player bullying and platform, they appear to be succeeding. Sea of Thieves releases sometime in 2018 for Xbox One and PC.