Originally Posted by barefootnavigator
I do this for a living and that appears to be a **** job from the factory. There is no evidence indicating anything other than a crappy build, yet another reason not to purchase a cheap **** production boat. That being said it is an easy and cheap repair. Fix it for get it and sail on my friend.
Hmm, you can tell that from one photo, huh? What exactly do you do for a living? Are you a boat builder or a surveyor?
To me it also looks like it could have been water intrusion that froze and split the rudder, or a grounding, or manufacturing defect, etc. It appears that the rudder may be rubbing the hull. The OP should confirm or deny this.
Only a close, in person inspection by a qualified marine surveyor can determine what caused this.