Once Human is taking base building out to sea. Its ocean PvE scenario, Isles of Abyss, is scheduled to arrive on PC, console and mobile after the October 21, 2026 update, according to the announced PT calendar. Players will be able to construct ships that function as mobile territories. This schedule does not confirm that servers are already open.
A ship that carries your base
In the October 21 announcement, the team describes ships built through construction mode. Making a vessel a mobile territory connects building directly to maritime exploration: the base itself can travel, giving players a way to take their construction onto the ocean.
Ship blueprints can be saved as a Design Layout and shared with friends. This lets players exchange ship designs, but the announcement does not establish whether construction resources can also be transferred.
Exploration also brings environmental pressures. Haywire Zones affect visibility, temperature, sanity and supply consumption. These conditions can change both what players can see and the provisions a journey consumes, making the environment another consideration when planning an expedition.
Underwater, the Oxygen Tank activates automatically when oxygen runs out and replenishes it. Players therefore do not need to trigger it manually at that moment.
Purification changes the server’s timetable
The scenario’s main cycle lasts around 21 days, with two phases followed by a rest period. That figure describes the progression cycle, not a deadline after which Isles of Abyss will disappear.
The first phase lasts approximately 5 to 10 days, becoming shorter as the server’s purification advances. The second phase lasts 11 days, and server purification unlocks the final challenge, The Sunken Lord.
Server-wide progress therefore affects both the pace of the opening phase and access to the final encounter. The opening stretch has a variable duration: players cannot rely on its maximum announced length when considering how the scenario will unfold.
How new characters enter the scenario
For new characters, registration comes after character creation and the early-game experience. Players then sign up for Isles of Abyss through the scenario selection screen. Before downloading, the team also advises allowing enough storage space: it warns that this update’s client is large.
The update separately announces an ocean map for RaidZone mode, Isles of Abyss: RaidZone. It is a distinct addition; the PvE scenario’s phase lengths and purification rules should not automatically be applied to it.
Mobile territories give shipbuilding a practical role in ocean exploration. Reaching the final challenge also depends on the server’s purification progress, tying the scenario’s progression to more than a player’s own preparations.
See also the Once Human game page, our article on Once Human: Isles of Abyss opening after the update and our article on Once Human: Isles of Abyss arriving after maintenance.
