Through-hull gate keeper


Though some voyagers have been known to sail in boats with one or none at all, most cruising boats have several through-hull fittings. These represent holes in the boat that could become a big problem if a hose or a through-hull fitting itself were to suddenly fail. What if there was a reliable way to close all your boat’s seacocks with just a push of a button? A new product from a small company in Maine called Graylock, which hails from Cranberry Isles, now has developed an automated through-hull product that does just that using compressed air.

No captain should leave the dock without a diagram showing the location of every through-hull fitting on the boat. Each through-hull should also have an appropriately-sized soft wooden plug loosely attached to it. So if the need arises to close off a broken seacock, the plug can be hammered into place.

Of course, even if you know where all your boat’s through-hulls are located or are armed with an up-to-date diagram, it can be a challenge to reach some of the more out-of-the-way fittings. Add cold, flooding ocean water, darkness and the real possibility of sinking, and finding a failed through-hull and shutting down the flow of water can be a challenge.

It was hearing about just such a situation that prompted boatyard owner Edward Gray, one of the founders of Graylock, to begin working on a system that allowed boaters to remotely operate their through-hull fittings. “I had the idea when talking to a friend,” Gray said. “He was sailing to Bermuda when a hose sprung loose. His boat had eight seacocks and couldn’t find the leak. Because his batteries were mounted low down in the boat, they got wet and he lost electrical power.” Gray said. The friend eventually found the faulty fitting and was able to save his boat. Gray, who owns Newman and Gray Boatyard on Cranberry Isles with his son Josh, decided that a pneumatic system that didn’t rely on electrical power was the way to go. The system has several components: a small electrically-driven compressor, a customized control panel, the Graylock valves and a reservoir air tank.

The only electrical requirement is for filling the air tank. For many voyaging sailboats, the compressor can be run when the engine is running for propulsion or battery charging. For boats with a genset, the compressor can be run anytime. Once the air tank is pressurized, the system doesn’t need electricity. It can be operated using an air switch from the control panel. A flip of the switch routes air from the tank to the Graylock valves, which are through-hull units mounted with compressed air actuators. The power of the air closes the valve (the valves can also be operated manually with the attached handle).

According to Gray, a two-gallon compressed air tank has enough pressure to operate a one-and-a-half-inch seacock 15 times. The valves can be closed individually or in groups. One advantage to the system is that it allows boat owners to easily add air-powered accessories like horns and the ability to blow up inflatable dinghies. Many voyagers carry compressors for recharging their scuba tanks. Gray said his Graylock system could be run off scuba tanks by using a regulator to bring the pressure down to the Graylock operating pressure of 85 to 105 psi.

Gray said his company has been testing the Graylock system on a water taxi that operates between Southwest Harbor and Cranberry Isle and have been encouraged by the reliability of the system in temperatures between 0° and 80° F. According to Seth Gray, Edward Gray’s other son and the company engineer, pneumatic valves are widely used in industrial applications.

According to the company, the Graylock system has been installed on roughly 10 power vessels such as the Southport 30, Newman 32 and 36, a Bunker and Ellis and some custom cold-molded launches. Even though one of the original inspirations for the patent pending system was a voyaging sailboat, Gray said no systems have been installed on sailboats yet. Gray said he is meeting with Hinckley and Morris Yachts boatbuilders, who have expressed interest in the Graylock system. Graylock also had a booth at the recent Maine Boatbuilders Show in Portland, Maine. According to Gray, it was the company’s first foray into the recreational boat show arena.   

Remote vessel monitoring
Knowing your boat is safe at its mooring or in its slip certainly adds to an owner’s peace of mind. There are several ways to keep electronic watch over your boat (or your fleet). You can keep track of just a basic high water alert or a high bandwidth multi-sensor lockdown.  

A good example of what happens when an owner does not have this knowledge is told in this issue by Robert Beringer. Even the happy excitement of Christmas Day wasn’t enough to distract Beringer from worrying about his boat. He had been having problems with his bilge pump the week before and became concerned that his boat was sliding beneath the waves. With no remote monitoring system installed on his Catalina 34, Beringer had no way of knowing what was happening an hour’s drive away. Finally, he gave in, got in his car and made the trip. He was happy he did.

One of the players in the world of remote monitoring is Global Ocean Security Technologies (GOST, based in Fort Lauderdale, Fla. GOST’s Phantom system is the company’s flagship product. Even the basic $1,299 version of the Phantom is a highly capable remote vessel monitoring system. It can support up to 64 wireless sensors for security and monitoring and eight wireless relays to control any AC/DC functions on board. The Phantom can text message you should any of the sensors alarm. It has a built-in speaker phone, so a remote owner can talk to someone on the boat and get a real-time report. The Phantom system has a wide range of capabilities and can be extended to do just about anything an owner might need in remote monitoring.

On the other end of the monitoring scale is the small, lightweight Pixie unit from Siren Marine ( With a just a few connections, the $499 Pixie can monitor position, bilge water level, battery level and temperature. This unit uses text messaging via the cell phone network and has a built-in battery that reportedly can operate for four days without the need for a battery recharge.

Either of these or other vessel monitoring systems would have let Beringer know early on that something was amiss with his boat — no gut instinct needed.

By Ocean Navigator