Hull to keel joint : somebody tried to glass over the joint on the boat with the engine mounting cracking. Surveyor was worried about what it hid.
Expect though to see a 3-5cm horizontal crack at fore and aft end of keel - this is just caused by the hull flexing slightly fore and aft of the keel bolt fixing points, this happens during lift out and storage on its keel.
I was advised not to let the boat dry out on its keel, although it has not suffered yet from scrub-offs on the Hamble piles.