Once Human Isles of Abyss release date: the free ocean expansion is out on PC, PS5, Xbox and mobile

Once Human’s biggest free expansion is out, and it moves the survival game from land to sea. Here’s when Isles of Abyss launched, what’s in it and how to get in.

When did Isles of Abyss come out?

On Wednesday, Oct. 21, 2026. Starry Studio started the update maintenance at 4 p.m. PT, or 7 p.m. ET, and planned about three hours of downtime before the servers opened. The update hit PC, PS5, Xbox Series X and S, iOS and Android together, which is why the PlayStation Blog gave the PS5 date as Oct. 22, or Oct. 21 in the Americas.

The first batch of servers opened right after the update: four in North America and Europe, and two each for South America, Japan, Korea, Southeast Asia and Hong Kong, Macau and Taiwan. Each server holds 12 worlds, and Starry Studio opens more servers as the first ones fill up. A first fix, patch 3.1.1, followed on Oct. 22.

What is Isles of Abyss? A PvE survival scenario set on an ocean archipelago, from tropical coconut groves to frozen tundra. The ocean itself is the enemy: a conscious entity called the Sunken Lord, whose lighthouses and ghost ships drift through the fog. Regional threats include fog, black tides and fire raining from the sky, and regional bosses wait in giant towers.

Players start on a beginner island after a shipwreck, then explore the other four ocean regions in any order. Two new characters guide the story: Malla, a captain who senses the pasts of the drowned, and Ran, a sharp investigator with an old debt to Malla.

Ships, sea fortresses and diving. Every voyage starts on a basic wooden raft, and that raft grows into a mobile Sea Fortress that works as a base, a workshop and an artillery platform. Starry Studio leaves the design open, from a pirate ship with broadside cannons to an industrial drilling rig or a sci-fi aircraft carrier, and friends can sail together as a fleet.

Land and sea feed each other. Island resources build naval tech and heavy weapons, and the deep sea gives materials for gear and bases on land. Underwater, players dive into sunken ruins for treasure, harvest rare resources and hunt deep-sea creatures.

The core cycle runs about 21 days. Phase I lasts 5 to 10 days and gets shorter as the server’s purification progress advances. Phase II lasts 11 days and unlocks the endgame challenge against the Sunken Lord. A rest stage follows both phases.

The permanent server for Isles of Abyss opens on Nov. 18, 2026, PT, before the first servers close, so every player can merge into it.

Launch rewards sit in the in-game mailbox until Nov. 8 at 2 p.m. PT: a new Legendary weapon blueprint, a Legendary gear blueprint, 10,000 Starchrom, a 30-day Meta Pass trial card and a limited weapon skin. The next update is set for Nov. 4 at 3 p.m. PT.

Once Human was the No. 2 free-to-play download on PlayStation Store in the US in September, according to Sony’s September chart. For other games launching this week, see our new games this week roundup.

This page is updated as soon as Starry Studio dates the S5 Vision servers for Isles of Abyss or changes the Nov. 18 permanent server date.