Mysterious viking ship at Isle of Thunder

[Haleth]

So I was doing dailies at the Isle of Thunder when I noticed what seemed like a large viking ship off the west coast, near the Court of Bones. It was moving, unlike the Silver Covenant and Sunreaver ships nearby. When I got closer, it disappeared. I used my water strider to look around on the water, but nothing. Shortly afterwards I saw it again near a similar spot, but as I approached, it disappeared once more. I never saw it again afterwards despite looking all around the island.

Only picture I managed to get:



I did find a similar looking ship at the east coast (at the area that's still locked off), but it didn't move.

I couldn't find anything about it. Does anyone by any chance know more (or saw it as well)? It really intrigues me for some reason