Karen, We have a 2004 hull, and it did the same thing when we bought it used. As I recall, there was a functional flapper valve to prevent this, but there was not enough back pressure to close it all the way. Since we love our boat and there seemed to be no simple workaround, we just put inexpensive valves in the drain hose and close them under ordinary circumstances. M17s run pretty dry, so a sponge has taken care of the occasional wave. If you are contemplating a long bluewater passage, you probably should leave the valves open and wear neoprene booties or sailing boots, which you probably would anyway if you are taking waves and the water is cold. Tom Jenkins M17 Scintilla On Dec 1, 2012, at 5:46 AM, Karen Saville wrote:
We have a Montgomery 17, 2006, and when our boat is heeling or motoring the cockpit drains back siphon water into the cockpit. Are these one-way valves? And is it normal to back siphon or are these valves defective? Any help or answers would be appreciated!!! Thanks!