Bea, I'm sorry but I doubt that this light come's from Mohni lighthouse. It must be more to the left and out of our view. We haven't seen it all the time and lighthouses usually blink, but this light is steady.
I think it's a ship, sometimes they stand there for a long time waiting something, probably their cargo to get ready and waiting in harbour is too expensive.
There's a fine site to follow the ships, I took a snapshot of it. It shows that exactly in this direction of the mysterious light stands a ship Minerva Alice. It seems to be rather far, I don't know if it's possible that we can see it's light.
