Hi Bert, Ironically, I was thinking of the "unmentionable" on the drive back from my boat today. It doesn't quite answer your question, but what about using a 3 gallon bucket (from Home Depot) with comfy seat attached & bio-disposable bags? If you are sailing out in the "wild blue," include a 2 lb. rock to the mixing and let 'er fly (I did say it was "unmentionable")! Your "Unmentionable" neighbor located a few docks down. Scott Simpson West of One 300 3rd Street, # 903 San Francisco, CA 94107 415. 328.2668 scott@westofone.com www.westofone.com