Which preposition to use with bothnia

to Occurrences 3%

Four days of rough weather in the North Sea and the Baltic brought me to the Swedish capital, whence on the following day I took the small steamer which plies three times a week around the Aland Islands, and then across the Gulf of Bothnia to Korpo, and through the intricate channels and among those low-lying islands to the gray lethargic town of Abo.

toward Occurrences 2%

The little ship was crossing the Gulf of Bothnia toward the coast of Sweden.

Which preposition to use with  bothnia