We need to understand how our C Dory 22's are built. The basic hull is molded in one piece. The inner bottom is the floor in the cabin, at least thru 2007, and reviewing photos of boats constructed thru 2016, I believe much of this to still be the case today. (The venture series (for certain the 26) and Tom Cats, have an interior floor elevated off the bottom of the hull).
Some boats had the aft cabin bulkhead put in place--then the molding of the entire deck, including the gunnels, splash well entire cabin house, less top, installed. The hull to deck joint is glassed over both just below the gunnel, and across the transom, underneath the trim pieces. The aft bulkhead should be tabbed into the hull, both in the cabin and the cockpit area. In many boats there is a slot or hole cut between the inner hull bottom under the cockpit, and the cabin floor(inner hull bottom), so that a bilge pump can be put in place forward the aft cabin bulkhead, where the lowest place is when the boat is in the water. In the newer boat (sometime late 2006/2007 on) where a fixed molded floor is placed in the cockpit, and should be totally sealed off from the hull bottom (but is not, and this is the source of the water under the cockpit floor). The entire V berth, and molding under the portipotty location is another piece which is tabbed into the sides of the hull, and should be tabbed into the bottom of the hull all along the bottom of this V berth molding.
Tabbing is using continuous pieces of fiberglass mat 3" to 4" wide, set in resin to completely seal off the V Berth components from the cabin floor, and the aft bulkhead from the cabin floor. Thus water trapped under the V berth/portipotty area, should not get onto the cabin floor, nor should water trapped under the glassed in aft cockpit deck get into the cabin, if the aft bulkhead is properly tabbed in place. The problem lies, in that often the glass pieces to be joined are not clean--there can be wax, dust, and other contaminates, which keep the resin from bonding the glass mat to the bulkheads and molded areas. I have not looked carefully on how the totally molded interior is tabbed in--but the general principles apply. Unfortunately there is often incomplete bonding, or breakdown of the adherence between the bulkheads and the hull bottom, which allows water intrusion into the cabin floor. When we were building boats we tabbed in bulkheads with initially 2 layers of mat, and then a layer of 24 oz roving, mat, roving, mat, cloth. Production boats take shortcuts to build to a price point.
Also all penetrations thru a cored structure should be have the core sealed. This has never been done with C Dorys at the factory to my knowledge. I discussed this with one of the C Dory owners and investors at the Hontoon gathering, and in an followup e-mail. If there is water getting inside of the cabin--there is a failure in the boat building process. (Almost all production boats have this issue, lacking an owner who pulls the railings, penetrations etc off, and re-seals. ) When we re-built our Cal 46, I spent over 2 months pulling all railings and fittings, properly sealing and bedding, 25 years later that boat is still cruising full time, and not a drop leaks inside)
On the wooden interior C Dory 22's the tabbing on the inside of the cabin should be able to be checked, and repaired if leaking. It can also be checked on the removable floor/no floor cockpit boats on the outside of the aft bulkhead. It should be able to be addressed on the molded interior boats, but may be a little more difficult.
If I have missed any information on the newest boats, please correct me, and inform us what is different.
