When all else fails, read the directions, Sam...
If you had when you'd installed the Cricket, you'd know that the Cricket WILL flush "as advertised" on ANY boat, whether the pump is below the waterline or not--IF it's installed correctly. You must not even have bothered to take the manual out of its plastic envelope--because it's right on the very first page and in bold print (you can see for yourself on the Raritan website at http://www.raritaneng.com): "The Cricket marine toilet can be installed above or below the waterline. However, for mounting at or below the waterline, vented loops must be installed as shown in Fig #2 to prevent back-siphoning." "Fig #2" clearly illustrates a vented loop in the intake line, installed between the pump and the bowl.The same is true for the PH II...from the manual (in bold print):"Warning: below waterline installations require vented loops..." If didn't install one , you didn't read the directions for installing the PH II either. You should have...because the PH II installed below the waterline (and all other toilets that have a pump beside the bowl instead of under it as the Cricket does) is even MORE vulnerable to overflowing than the Cricket, because a bowl sitting beside the pump is lower in the boat than a bowl sitting on top of the pump...more of the bowl is below the waterline, and the pump won't prevent the water from rising in it if the dry/flush valve is ever left on flush, or the valve should fail. The above doesn't only apply to the Cricket or the PH II...it applies to ALL toilets: if ANY part of it is below the waterline, a vented loop at least a foot above the waterline MUST be installed in the intake between the pump and the bowl.People are fallible...mechanical parts can fail. Relying on fallible human nature to never forget to leave the valve set to dry, or on a mechanical part than can and does (more often on some make/models than others) fail to protect your boat just about guarantees that the day WILL come when you'll get a call from your marina that it's sunk in its slip. If you don't close all the seacocks each time you leave the boat either, you're at an ever greater risk...open seacocks--especially toilet intake seacock--are the most the common cause for boats sinking in their slips while the owner is away.Ed, you'll be very happy with the Cricket if you'll just follow the installation directions.