by VeganTnT
We had difficulty with this rule as well but decided on our own that the Monster in the Bay moves to the City.My reasoning was that not only does the monster in the Bay have seniority by already being on the board, but in keeping with the theme the monster in the Bay is physically closer to the city. If a monster in the Bay saw the City being vacated it would rush in and take advantage of the situation.
Works well and no penalty for being locked into the Bay.