Fresh Water Gauge

Here’s a very simple way to add a fresh water level gauge to your tank without drilling any holes. Just T in a clear hose near the tank’s existing output hose and run it above the tank to see the water level!The clear hose must be open at the top end to allow the water to move freely, but add a valve for when you are underway. You don’t want the tank water to come out while heeling.

My system uses all 1/2″ interior diameter hose, so I just matched that for the clear hose.

To add graduated markings to the hose, I added 5 gallons at a time, marking the hose at 5 gallon increments. Rather than filling a 5 gallon bucket and attempting to funnel it into my fill-port, I timed how long it would take to fill the bucket with the water hose on full blast (45 seconds). I then added 45 seconds of water into the boat’s water tank. Close enough for government work. The tank on my Cal 39 was advertised as 50 gallons. I ended up adding 49 gallons using my method, so I must have been 1 gallon off.

Simple, cheap, effective.

Negative comments: The level indication moves around quite a bit while underway and varies depending on the tack I’m on. Averaging seems to be pretty accurate. It’s spot on in a flat calm, though.