Conduit in a mast is a relatively easy task if you have the mast on saw horses in a yard.
Buy PVC to serve as conduit.
Reach inside the mast with something like a 2x4. You what to position the conduit on top of the 2x4 being held against the mast.
Drill a hole through the mast and conduit.
Slip a small rivet into the hole and pull the conduit up to the mast with the rivet.
Continue working your way along the mast spacing the rivets about ever 2-4 feet in a straight line.
Enough to hold the conduit in place.
Pass your wires through the conduit and wire up the lights or transducer as needed.