My buddy was pumping off the dock today when he fell on top of the foil and his weight ripped the mast out of the box...definitely too shallow. I am wondering if it can be repaired and where to look/go to if so. The board is a Core SLC 115x46. Any advice or input regrading if it can be fixed would be super helpful here.

Because I am a new user it won't allow me to post photos. For a description:

The outer shell of the board is ripped at the end of the box closest to the nose of the board, but attached at the back in, though there are cracks. Their is a piece of the inside rail broken off on each side. The center shell of--between the two rails--is unattached and can be pulled up away from the board. I cannot see any damage to the structrue of the board itself. It is mostly to the shell around the box.

Sounds like something that'd be repairable by any reputable board builder /repairman, as long as damage is confined to the area immediately surrounding the tracks, and would end up stronger (if a little heavier) than new.
But you might have to give your location if you want recommendations to do this job.

The foil tracks are usually set into a piece of high density foam which is usually brownish-yellow in colour. Does your one look like that?

That stuff should be bullet proof. That box tearing out would explain the damage to the board.