Still on a raft?

Anyway the simple answer is to not sail at night.

The swamp is particularly bad since the ocean biome practically hugs the coast. So stay away from swamps at night.

The safe way is to go ashore for the night. Mistlands isn't a bad option at this point since it is not populated yet.

Meadows and Black Forest tend to have decent water areas before ocean so finding a spot to sit out the night on the water isn't bad either.

The last thing you want to do is blindly sail into a plains at night.