Well, if you have had guests aboard, you already know "that guy". He's the one that arrives empty handed, packs a huge hard-sided suitcase, drinks all of your booze, and wastes huge amounts of water.   You can hear that faucet running in the head, and watch the water tank levels dropping. 

Most boat and RV faucets have dual twist handles, which make it especially difficult to conserve water when brushing your teeth, washing up, or getting a quick splash of water at the galley sink. 

Well, the simple little Water Saver from Marinebeam solves this issue, and really makes a huge difference in water usage.  It actually makes using the faucets simpler as well.

We first noticed these decades ago in the public restrooms in Mexico, and thought they were brilliant compared to the unreliable automated sensor faucets we had in the States.  We also thought that they would be great for boats. Water is a scarce resource on-board, and these gizmos are foolproof, no matter if "that guy" is still aboard.  

You simply push your hands against the vertical spring-loaded toggle, and it opens up a valve allowing the water to flow.  Push it further, and get more flow.  A lighter touch gives just a trickle.  Let go, and the valve snaps immediately back into place, and the water stops instantly.  Perfect for lathering up with soap, or when sanitizing your hands after handling raw foods.  You never even need to touch the faucet handles (or dry them back off).  Also minimizes splatter and soap residue around the handles.  It also solves dripping faucets by adding a second water-tight valve after the leaking seal.

Takes just seconds to install.  It consists of a little ball-valve on a toggle which threads right into the end of the faucet. You just remove the original aerator and install the Water-Saver.  Fits almost all standard boat faucets right out of the package, but Marinebeam carries optional adapters for odd-ball faucets and obscure European designs. 

We sell these like crazy at the boatshows, and people return every year to thank us and sing its praises.  It is a product that really sells itself in real life, but is a slow seller on the website.
 

It is a very low cost boat product that has an immediate payback is water savings.  Pick one up for yourself, or as a Christmas gift for a cruising friend.  You'll be glad you did.