I hired a boat to the castle and whenever I'm on that small Island and click the boat to get to the castle, the loading menu shows up and then it crashes....does it happen to anyone else?

No... I'd suggest swimming there?

I've crashed a couple of times at the start of this DLC. Though I've never had this issue. I've only really crashed when I walked to different spot for some reason. And Toggle no clip took care of that.

As for your problem? Just keep reloading, and hope for the best?