When using a boat, the positions of the player and of the boat will be desynchronized.

Usually, the speed of the boat client-side will be higher than server-side. When arriving to a specific zone:
→ The player, when leaving his boat, will appear in the sea. The distance between the two desynchronized positions depends of the distance travelled.
→ Server-side, the boat is next to the player after he left it. But the player will be unable to see it.
→ A ghost boat remains on the location where the player has left the boat. It is not possible to interact with it.

Disconnecting/reconnecting solves the problem; the player and the boat will re-appear to the server-side positions.