Figuring out what to do when nature calls on the water has been a problem since man started messing about in boats. At some point, we even decided to become more “civilized” by using marine toilets. But that’s when we also overcomplicated the whole business.
Today there are all sorts of marine sanitation devices (MSDs), and there are also lots of regulations that dictate how you can and can’t install and use them. It’s a subject that’s constantly confusing boaters, so let’s get right down to demystifying the most basic part of any sanitation system on a boat: the marine toilet, or “head.”
Short of a bucket, the simplest device to deal with onboard sewage is a portable head, aka porta-potty. This type of MSD has its own integral holding tank and refillable freshwater supply tank. You simply do your business, actuate a hand- or foot-operated pump, and then the water flushes away the bowl contents into the holding tank. When the tank is full, you take it ashore and empty it into a suitable toilet, or give it to a pump-out facility equipped to handle it.
A manual marine head consists of a porcelain bowl, a hand-pumped raw-water intake, and a discharge elbow. Once the user has made a deposit, he or she actuates the pump by hand a half dozen or so times. The up stroke of the pump draws water into the bowl and flushes away the contents, while the down stroke expels the waste through the discharge elbow.
An electric head incorporates an electric pump that creates suction to pull in water and also expel waste from the bowl. That pump usually macerates (chops) that waste as it is being discharged, too. The user just presses a button until the bowl is clear. Another type of electric head uses an electric pump to create a vacuum that pulls waste from the bowl back into a tank for holding—simply step on a foot pedal and everything in the bowl magically vanishes. SeaLand’s VacuFlush is one brand of vacuum head you may have heard of.
And yes, believe it or not, there are even composting and incinerating toilets that can be used on boats, but they are certainly specialized, and not the norm. Portable, electric, manual, vacuum—all sounds easy enough, right? Well, not so fast.
You can’t simply install one of the aforementioned marine heads and have it discharge overboard. Since it is illegal to discharge untreated sewage into pretty much any body of water in the United States, that means these heads must be plumbed to a holding tank or treatment device. Which, unfortunately, requires Y-valves, vented loops, specialized hose, and more words to explain than will fit in this short blog.
So, once you’ve had a chance to check out all the different types of marine heads out there, keep an eye out here for Part Two, when we’ll discuss the legal ways to install a new head and holding tank, or retrofit an old one to comply with overboard discharge laws.