As Witch how do I win?

[pgm1961us]

Hello!
My character is the Witch. I have been playing as the Witch for 3 weeks solid now. There are no more independents; only the occasional Merchant. My Commanders are armed significantly, my Witch and apprentices are exceedingly fortified. All villages, farms, et cetera are in my possession. All forests are in my possession. The entire board is green, all islands that I can find are exposed.

Except for 3 black squares that cut into the shore line! How do I expose these squares? I am at a complete standstill at this point.

Any guidance that you can share with me I would appreciate it. If it would help I can email you the saved board. Just let me know.

Thanks in advance!!!

v/r, pgm...