BoatTracking

Name your boats by holding E.

All boats are visible on the map from anywhere - even across the ocean, even when nobody is near them. Unnamed boats will use their type name.

Use in single player, or multiplayer. For dedicated servers see install instructions below.

Install (multiplayer / dedicated)

Open r2modman / Thunderstore Mod Manager → Valheim.
Install BepInExPack_Valheim if you do not already have it.
Online → search DevDonkey-BoatTracking → Install on your client profile.
Install the same package on your dedicated server profile (or copy BoatTracking.dll into the server BepInEx/plugins/ folder).
Restart the server, then launch the game through the mod manager.

If client and server builds get out of sync, you will see an in-game warning asking you (or the host) to update.

Same package via r2modman is enough - the local host acts as the server.

Manual: put BoatTracking.dll in BepInEx/plugins/ (needs BepInExPack_Valheim).

Look at a ship and hold E to open rename (tap E still boards / steers as normal).
Names show on the minimap and full world map.
Unnamed ships still appear as Raft, Karve, Longship, or Drakkar (config can hide unnamed ones).

Raft, Karve, Longship, and Drakkar (Ashlands).