Raritan Tank Monitor 12V for Fresh, Gray and Waste Tanks

The Raritan Tank Monitor is the cleanest way we know to keep an eye on what's happening inside your boat's tanks without ever cutting into them. One flush-mounted panel at the helm or in the head, and you can read up to four tanks at a glance. Fresh water, gray water, waste, it handles all three. Tap the tank you want on the touch pad and the panel shows you where it sits at quarter-tank steps: empty, a quarter, half, three-quarters, or full. Simple international symbols, no guessing.

What sets this system apart is that nothing lives inside the tank. There are no probes dangling in your holding tank, no floats to gum up, no special fittings to drill and seal. The sensing module mounts on the outside of the tank wall and reads the contents through it. That matters more than it sounds. Anyone who has fished a fouled float sensor out of a waste tank on a hot afternoon knows exactly why external sensing is worth paying for. Here, the electronics are fully encapsulated and sealed against the marine environment, the connectors are gold-plated so they don't corrode and drift, and there are no moving parts to wear out.

It works on non-conductive tanks, which covers just about every polyethylene or fiberglass tank you'll find on a modern boat. Fresh-water tanks read dead accurate. Waste tanks read reliably too, though the density of what's in a holding tank can vary, so give it a little time to settle before you trust a borderline reading. One important limit: this is not for fuel tanks, and it won't work on a metal tank without proper isolation. If your tank is aluminum or steel, this isn't your monitor.

Installation is about as friendly as marine plumbing gets, because you're not opening the tank. You mount the sensor module to the outside of the tank, run the leads back to the indicator panel, and give the panel a flush cutout wherever you want to read it. The panel sits smooth against the bulkhead with no protruding switches or knobs to catch a hip or a dock line. Wire the 12-volt supply straight to a panel circuit or the battery so the display gets clean, steady voltage. Low voltage from a long, loaded run is the usual culprit behind a monitor that reads low, and you'll dodge that with a direct feed. The whole unit sips power, so you can leave it live without worrying about your house bank. Plan the panel location before you start, somewhere dry and easy to glance at, and keep the sensor leads clear of bilge water and moving hardware.

A word on where this fits. It's a standalone indicator, not a networked sender. It won't push tank levels to your chartplotter or show up on an MFD tank page. If you want everything on one glass display, that's a different setup. But for a dedicated, dead-reliable readout right where you live, in the head or at the galley, this is exactly the right tool. It pairs naturally with the rest of a Raritan system, so if you're already running a Raritan head, adding this monitor keeps your whole sanitation setup under one roof.

Raritan builds these one at a time. Each unit is assembled by hand, individually tested, and backed by Raritan's one-year limited warranty and a tech support team that actually knows the product. We've sold Raritan gear for years, and it's the kind of equipment that just keeps working. For a cruiser who wants to stop guessing about the holding tank before a long weekend, or a liveaboard managing fresh water carefully, the Tank Monitor earns its spot on the panel.