Thanks for the interest Jaysen, cape man, Jeff, Tom, Fuzz and Barra Man.
Apologies for not answering your questions these past few days about hull holing size and staying afloat.
I’ve been totally focussed on the repair job and antifouling the whole hull. These are nearing completion, and we hope to be back in the drink in 48 hours.
And so, to the question of hull hole size and staying afloat.
The answer is in two parts, because Great Sandy’s hull skin consists of two layers of timber planking, each 1/3” thick and approx. 6” wide, and each running at 45% to the centreline of the boat and at 90 degrees to each other.
The coral had ground out a hole in the outer skin - approximately 3” in diameter on its outer face tapering down to around 1” in diameter on its internal face. The outer plank had not fractured, it had been ground away.
By way of contrast, the inner plank had a triangular fracture, its base at the junction of the plank and the keel plank/hog to which it was epoxy welded to. The other two sides of the triangle were ragged tapering tears all the way through the plank. The force of impact had partially snapped the inner plank along the hog line, but fortunately not all the way through. The remaining intact timber acted as a baseline hinge to the triangle, its jagged apex was sitting approx. 1/8” proud, and water was flowing in.
I was able to largely staunch the flow by using timber wedges to force the hinged triangle closed and firmly in place. The bilge pumps where then able to cope.
The first pic shows the removed triangular section sitting on the mahogany plank used for the repair. The teaspoon is for scale. The following pics show aspects of the tearing or fracturing of the inner plank. The last pic shows the junction of the keel plank/hog and the inner planks after the triangular piece's hinge was cut with a chisel and the triangle removed.
Currently building Jacques Mertens ST21 "Skinnydip". Boating adventures: Splash testing and using 'Skinnydip, as a basis of further building refinement; Adams 44’ sailing sloop "Great Sandy" (cruising and maintaining); Iain Oughtred Feather Pram "Mini Dip" (building); Jacques Mertens R13 "Wood Duck" (built and due for maintenance).