Mike, I do not believe that such a fitting is available. PLUMBILL’s suggestion may be possible, but I think that it will leak during rough water conditions, and this Rube Goldberg approach will allow sewer gasses into the cabin.
I think that a flexible connection should be made outside of the cabin and under the water. Reduce the outlet pipe to 3-inch and connect a section of flexible RV plastic sewer hose. You can purchase the various fittings to complete the connection at a RV supply store.
» This message has been edited by John Aldrich on 16 May 2006
» This message has been edited by John Aldrich on 16 May 2006