Related to this discussion, I sail the Chesapeake Bay where pumping overboard is, of course, forbidden which leaves only deck pump as the only other option for boats with a holding tank. Soon after I bought our E32, many years ago, I changed out all of the head hoses and holding tank (along with rebuilding the head itself) because of the odor. It was a job I'll never forget and all I can say is that I'm glad I had raised small children during my life because the olfactory insult of changing out head hoses was similar to diaper changing but that's another story.
As part of the upgrade I removed and eliminated the "Y" valve ,cause it was no longer needed on the bay, ensuring that deck pump out was the only option. A few years later we we boarded by the US Coast Guard while we were underway and sailing to St Michaels, MD from Annapolis. Besides the usual check of our boat papers one of the Coast Guardsmen (it is that now Gards-persons?) asked to see my "Y" valve for inspection to ensure that it was locked in the closed position. I said, "I don't have a lock and neither do I have a "Y" valve." A look of terror came over his face (I'm not kidding) at which I said that he could look for himself. Upon opening the door to where the thru hulls were which I had closed and blocked off with no hose going to it, he finally realized that there was a direct route from the head to the holding tank with no option to pump overboard. A big smile came over his face (Again, I'm not kidding.) and I said, "See no "Y" valve, lock or pumping overboard." He was a young lad (he still had sone acne) carrying a 9 MM on his hip and was over joyed which is good to see when someone is carrying a gun. In the meantime my wife was in the cockpit with the female guardsmen talking about shoes! (Once again, I'm not kidding.) After all was determined to be ship shape on board our little vessel we waved goodbye to our coast protectors and with that the training exercise for the day ended.
