How to Set Up a Sunkenland Dedicated Server

Sunkenland — the waterworld raft-and-base-building survival game — plays much better as a dedicated server than a hosted-by-a-friend session, since the world keeps ticking (tides, hunger, base decay logic) whether or not anyone's home. Here's how to get one running on a Linux VPS.

What you'll need

• A Docker-capable Linux VPS (Ubuntu 24.04 / Debian 12).
• 4 GB RAM minimum for a small group; 6–8 GB if you're running a full 8–10 player world.
• A little disk headroom — Sunkenland's world files and Steam runtime both live on disk (30–40 GB recommended once a world has been played for a while).

Step 1: Install Docker and prep directories

Sunkenland's server splits its data across three separate mounts — worlds, game files and its Steam runtime — so create all three up front:

curl -fsSL https://get.docker.com | sh
mkdir -p /opt/sunkenland/Worlds /opt/sunkenland/game /opt/sunkenland/Steam

Step 2: Launch the container

Sunkenland's dedicated server is Windows-only upstream, so the community image wraps it with Wine — you don't need to think about that layer, just run the container:

docker run -d --name sunkenland --restart unless-stopped \
  -p 27015:27015/udp -p 27016:27016/udp \
  -e GAME_WORLD_GUID='my-world' \
  -v /opt/sunkenland/Worlds:/sunkenland/Worlds \
  -v /opt/sunkenland/game:/sunkenland/game \
  -v /opt/sunkenland/Steam:/sunkenland/Steam \
  melle2/sunkenland-ds:latest

Step 3: Open the ports

Sunkenland uses two UDP ports — one for gameplay traffic, one for server browser queries:

sudo ufw allow 27015/udp
sudo ufw allow 27016/udp

Connecting to your server

Once both ports are open, friends can find your world either through Steam's in-game server browser (search by name) or by connecting directly to your VPS's IP address on port 27015 — direct connect is the more reliable option right after first setup, since a brand-new server can take a few minutes to appear in browser listings even once it's fully joinable.

Step 4: Confirm the world persists

Give the container a minute to pull the Sunkenland dedicated server files on first boot (it downloads via SteamCMD internally), then check /opt/sunkenland/Worlds on the host — you should see your world's save folder appear. That folder is everything: back it up before updates the same way you would any survival game world.

Sizing your server

Sunkenland scales with party size roughly the way Valheim or Enshrouded do — a small raft crew needs far less than a full base-building group:

• 4 GB RAM / 4 players — a small crew getting started.
• 6 GB RAM / 8 players — the tier most groups land on once a base is established.
• 8 GB RAM / 10 players — a full server with multiple islands and bases active at once.

A note on mods

Sunkenland doesn't have Steam Workshop integration, but there is a small, real modding community built around BepInEx (the same mod loader Valheim and Sunkenland both use), with mods distributed through Thunderstore and Nexus Mods — mostly quality-of-life tweaks like inventory repair and adjustable building restrictions rather than total conversions. It's early days for Sunkenland modding, so treat this as a nice-to-have rather than something your server setup depends on.

Common first-run issues

• Container exits immediately: check docker logs sunkenland — this is almost always the Steam runtime still downloading on first boot.
• Friends can't connect: confirm both 27015 and 27016 UDP are open, not just one.
• World doesn't save: make sure all three volume mounts from Step 1 exist and are writable before the container starts.
• Server seems to "restart" a fresh world: double-check GAME_WORLD_GUID is the same value every time you redeploy the container — changing it points the server at a different (new) world identifier instead of reloading the existing one.

Updating the server

Because the image pulls the dedicated server files via SteamCMD internally, a plain container restart (docker restart sunkenland) is usually enough to pick up a new Sunkenland update — the entrypoint re-checks for updates on boot. If a major update changes the save format, Wine-wrapped titles like this one occasionally need the image itself rebuilt against a newer base, so keep an eye on the melle2/sunkenland-ds Docker Hub page after a big content patch if the container fails to start cleanly.

Keeping an eye on resource use

docker stats sunkenland gives you a live view of RAM and CPU usage, which is the fastest way to tell whether your tier is actually sized correctly once real players (and real bases) are on the world rather than guessing from the numbers above alone.

Once you're past first boot, a Sunkenland server is genuinely low-maintenance — most of the ongoing work is the same as any survival game: watch disk use as the world grows, keep backups current, and check in after major updates. Nxeon's Sunkenland server hosting runs this same container setup on NVMe-backed VPS instances with the ports and volumes already wired up, so you skip the Docker plumbing entirely.