Hi,
I have taken EVERTHING off the deck of my Oday 26 and am in the process of repairing a considerable amount of cored deck. The Problem that i see is that ALL the through deck fittings forward of the cockpit,with the exception of the toerails and forward hatch, affect the core. I found a great deal of rotted core along the handrails, the hatch slides, the pulpit, the tabernacle, and of course the chain plates. Even the lifeline stanchions are mounted through the core (at least the inner two bolts are).I have found that my Oday has several areas of leaks that can run along the cabin liner and drain a considerable distance away. There is a small, approx 1/16th inch gap between the inner skin of my deck and my cabin liner. So any water coming in through a fitting can flow along the curve, the track of which depends on how the boat is lying when the rains come. For example, the water that leaks through the mast tabernacle can run forward, aft, and laterally along the liner.
keith