Money doesn't grow on trees and fuel isn't getting any cheaper so squeezing the most out of a gallon has become a major consideration. However, many boat owners haven't got a clue what the most economical operating range is for their vessel and one question is all it takes to know for sure. Do you have a fuel monitoring system on board? If the answer is no, you're contributing more to our dependence on foreign oil than you should, but you can change that by retrofitting a system in your boat and reaping the cost-saving benefits the first time you fire up the engines.

Every hull and engine combination has different operating characteristics and establishing the most economical cruising range is what a fuel monitoring system does best, but a good one also has side benefits. It is an early warning system for prop and engine problems and even bottom fouling, all of which increase fuel consumption. It can be an important part of trip planning by allowing you to reliably track overall fuel consumption and it can save you big on towing fees by telling you exactly how much fuel you have remaining in your tanks, thereby preventing you from running out.

Some of the latest generation boats are equipped with fuel monitors as part of the engine/gauge package, but the accuracy of some is suspect. I recently upgraded my venerable 16-year old 23- foot center console to a 2005 Mercury Optimax and a set of SmartCraft gauges, which include a very accurate flow meter, but I had installed a Floscan Cruisemaster system in the boat twelve years prior and it paid for itself three times over in fuel savings the very first year! It probably saves me $750 to $1,000 per year in fuel costs and its importance at the helm has steadily increased with rising fuel prices.

Brian Lewis chose a fuel monitoring system with gauges that replaced the existing tachometers. The retrofit took one day.

Floscan Instruments in Seattle, Washington, has been the industry leader in fuel monitoring systems for marine, industrial and civil aviation applications. Burt Rutans record setting flight around the globe without refueling in his experimental aircraft Voyager relied on Floscan monitors to chart fuel consumption in minute detail. But how do these little marvels save fuel dollars? Here's an example from personal experience.

In the years before I installed the original Floscan on my skiff I usually cruised at 4000 rpm with the GPS indicating a speed of 28 miles per hour. Actually back then is was Loran if you can remember those days. The big outboard ran smoothly so I assumed-there's that most dreaded word-t must be running efficiently. Boy was I wrong. I installed the Floscan and started doing the math. At 4000 rpm and 28 MPH the meter registered a steady 17 gallons-per-hour consumption.

Plugging that into a simple equation I came up with 1.64 MPG, which didn't seem very efficient so I started playing with different rpm combinations and jotting down notes. I finally determined that my boat's "sweet spot" was actually 4450 rpm at a speed of 36 MPH. Its fuel burn was only 18 GPH for an average of 2 miles-per-gallon, but I was baffled why I would get such an increase in fuel economy running the boat so much faster. Once I learned a little about hull dynamics the answer became clear. My skiff has a 20-degree deadrise, deep-V bottom with lifting strakes and operating at 4000 rpm it was on plane, but still had a lot of wetted surface in the water. At 4450 the boat was riding higher on the strakes with less wetted surface and less speed and fuel robbing drag. Without the Floscan I would have gone on my merry way burning 22 percent more fuel at cruise while taking considerably longer to get to my fishing spots without ever knowing.

Retrofitting a fuel monitoring system is far from difficult. Installation on a single outboard can be done in a couple of hours with the most difficult part of the job running wires from the flow sensor to the helm and drilling a hole for the gauge, if that is even necessary. A twin gas engine, inboard or outboard installation requires two sensors, one per engine, and takes a little longer. Diesel models are a bit more involved with most requiring two sensors per engine, one for the fuel line to the engine and the other for the return line from the engine back to the tank along with pulse dampeners. I've helped friends install all the variations over the years and found that if you?Ĵre relatively handy with tools and have a basic understanding of how the fuel system in your boat works, none have been so difficult that they required a mechanic. All have produced fuel-saving results that made the initial cost of the systems worthwhile, even if it required paying a mechanic to do the installation.

In the past six months I've helped two friends install systems. One went in a twin Detroit Diesel powered Egg Harbor 44 that I go offshore fishing on from time to time so I was pressed into service with the threat of losing my fishing invitation. Since this is the most complicated system it took a full day and the better part of a twelve-pack to complete with two of us working in concert. The other was in a Bimini Sport Express 24 with twin 150 hp Marine Power gas inboards. This boat is owned by my personal computer guru and fishing buddy, Brian Lewis, and if he's not happy, my computer isn't happy. He chose a Floscan TwinScan system with gauges that replaced the existing tachometers. The new gauges are set up with both tach needles in one gauge and both flow meter readouts in the other. It also includes a graphic engine synchronizer, which Brian absolutely loves. In addition, there is a digital fuel totalizer, a feature found on all fuel monitoring systems that tells you how much fuel has been burned from the tank. There is a digital MPH readout that works by linking the system to the on board GPS via the NEMA 0183 interface.With the GPS link you get a constant MPH reading instead of having to do the math which was necessary with the original Cruisemaster I had on my skiff. It makes finding the optimum operating efficiency of the vessel a breeze in any sea conditions.

With today's high cost of fuel, and no sign of a decrease to come, the use of a fuel monitoring system is your best hedge on rising prices.With more than a decade of experience with these systems in a variety of vessels, I know I would not own a boat without one and can attest to the fact that an accurate system can be the most important gauge at the helm station. Reducing the operating cost of your boat is that simple.

Fuel Flow System Suppliers:

Floscan Instruments, Inc.
3016 NE Blakeley
Seattle,WA 98105
206-524-6625
www.floscan.com