In looking at the layout of the Falmouth Cutter I am curious if the head (rim of toilet) is located below the waterline? If so do owners simply make a point of closing the seacock at all times to prevent an accidental siphoning? The Falmouth is such a well designed boat and I thought maybe I could learn what Lyle Hess decided to do. On my PS25 the toilet rim is located a few inches above the waterline and if lowered would allow me to increase the size and lenght of my v-berth.
IDUNA is fitted with a Lavac head which is below the waterline. Per the instructions, I looped the hose above the waterline - anti-siphon loops. It’s SOP aboard IDUNA to always close the intake and discharge seacocks for the the head.
Shaula’s SLM installed head was below the waterline. Cruising offshore with all the extra gear, had us down several inches from the official 4’10" draft. Once or twice over 29 yrs, we neglected to close the intake lever on the head, AND the intake seacock. Fortunately, we heard the tinkle of water overflowing the bowl and so the boat didn’t sink! There have been times when the WC Headmate needs overhaulaing and the shutoff lever doesn’t shut off the intake if the intake seacock is open!
Our standard practice is to shut off the intake seacock after every use. We don’t have a siphon breaker in the intake line, and it doesn’t loop up over the waterline. Our outlet seacock remains open except when we leave the boat for extended periods. It loops up almost to deck level, and has a siphon breaker at the top of the loop.