The early production NS36 masts had the lower wire exit placed in a location that has proven to be unsafe. It is located on the leading edge of the mast about 4ft. 6 inches from the bottom. As you can see it is right below the last fastener for the wiring conduit.

The crack has propagated about 3 inches horizontally out from either side of this hole. The reason this is a bad location for a hole in a Nonsuch mast is because of the aft bending of the spar. The bending wants to constantly open up the hole. If this is the situation that you have it is a good idea to pull the mast immediately and talk to your insurance company.