Plotting Your Course

In September of 1987, I sailed my 30-foot Hughes Columbia sailboat south to Little River, South Carolina. After a few days of waiting weather, I exited the Little River Inlet and pointed the bow towards Bermuda, some 1,000 miles away. To find that small speck in the middle of the Atlantic, I had the most up-to-date navigational instruments of the time. They consisted of a compass, VHF radio, a sextant with complete tables, paper charts and a radio direction finder. Seven and a half days later, I tuned the RDF to the radio signal for St. Georges Harbor and my feelings of accomplishment were beyond explanation.

Flash forward to the year 2000 as we were planning a trip through the Bahamas, Hispaniola and Cuba. We bought our first on-board computer with state-of-the-art navigational software and the most current electronic charts. We thought we had gone from the Santa Maria to the Starship Enterprise. Now, just 11 years later, that first navigational setup seems almost primitive. Today, we have a full complement of electronics, including our favorite, the chartplotter. We didn’t install our first chartplotter until our cruise from Houston, Texas to Beaufort, South Carolina in 2007. Once we had it on board, we wondered how we had navigated all those thousands of miles for all of those years without one.

Plotters are arguably the most popular piece of electronic equipment found on boats today. The advancements of plotters and GPS integration over the last 18 years are nothing short of astounding. In the early 90s, most all of us were still plotting our course on paper charts and using dividers, protractors, parallel rulers and a sharp number two pencil. Some time around 1993, all of that changed and the race was on for high tech, highly accurate electronic charting. In 1993, Raymarine introduced the Raychart 600 as an add-on to their radar system. The unit displayed on a CRT screen and the radar had to be switched off to view the crude monochrome display with little detail. In 1995, Garmin introduced the GPS Map 220. It boasted of viewing in 16 colors and retailed for over $2,000. These early chartplotters required expensive data cards or “chips” with limited storage space. A long distance cruiser might need up to 10 or more of these chips to cover all of their navigational areas. These chips were not updateable, so to have the most current, we would often have to purchase new cards if significant chart updates had been made.

In 2003, Raymarine once again made major headway with their introduction of the C Series and E Series displays with the ability to integrate other onboard electronics to the same screen. The term chartplotter was already becoming a thing of the past. True chartplotters are getting harder and harder to find today as system integration becomes the norm even on small recreational vessels. Today’s multifunction displays or MFDs can display almost every other instrument connected to the system. This includes radar overlays, wind speed and direction, boat speed, depths and much more. All of this while providing a position on the electronic chart with accuracy within feet of where your boat actually is on the planet.

The current offerings for MFDs are as spectacular as the improvements from 15 years ago. The new Raymarine e7 series, released in July 2011, contains a dual-core processor, touch screen technology and dedicated graphics for incredible speed and detailed display. The e7 has built in WiFi that will communicate with the Apple iPad, allowing it to be used as a repeater and much more. With the new LED backlighted screen, the e7 is incredibly bright and colorful, even in direct sunlight. The e7 can be integrated with Raymarine radar, night vision cameras, Sirius weather receivers, autopilots and other instruments and contains a 48-channel GPS receiver.

Not to be outdone, other manufacturers are also bringing out some outstanding products. Simrad has introduced their new touch-screen NSSSport Series. The NSS Sport comes in three sizes and offers touch-screen, keypad and rotary control to provide the user with a variety of user controls to fit their comfort level. Ensuring ultimate flexibility, the NSS Sport can be networked to the Simrad NSO and NSE multifunction displays, as well as Simrad Yachting’s comprehensive range of innovative performance module options, including the award-winning Broadband Radar™, StructureScan™ Sonar Imaging, SonicHub™ marine audio server and WM-2 SIRIUS^® satellite weather/radio module. The NSS Sport is also preloaded with Insight USA™ inland and coastal cartography, and is fully compatible with the complete range of Navionics chart options on microSD.

Garmin’s new GPSMap 6000/7000 touch-screen offers state-of-the-art G motion technology and built-in worldwide maps, XM weather radio compatibility and allows support for radar, sonar and more. The G motion technology give the user unprecedented viewing of navigational charts.

Many of the current displays include built-in charts for the entire United States coastal and inland waters. The need to purchase individual charting chips is also becoming a thing of the past. Satellite overlays, 3D imaging, weather overlays and video displays are but the beginning of more features, added capabilities and expansion we will see from all of the major manufacturers. As users demand more integration with other mobile devices and more computer-like capabilities, companies like Raymarine, Garmin, Simrad and others will quickly introduce new and more exciting products, a long stretch from my first sextant and radio direction finder.

A big word of caution is also needed with all of this technology. The temptation is great to fire up all of the electronics and head off into the sunset staring at your MFD and feeling you’re getting all of the information you could possibly need to navigate around the world. As great as these electronics are and with all of the information they can provide, they are by no means perfect. Nothing compares to a set of eyes constantly on watch for hazards and potential problems. No display can tell you if a log is floating in your path or if channel markers have been moved due to shoaling. Blindly following a plotter is a sure-fire recipe for disaster, and overly depending on any piece of equipment for the safety and security of your vessel and crew is foolish. We still keep paper charts on board because we have learned from experience that electronics can and do fail. When we want to look at the “big picture,” we can only do that on a set of the most current, up-to-date charts. We use a variety of sources for information and confirmation, and years of cruising and tens of thousands of miles under our keel have taught us that anything is possible. We want you all to stay safe out there.

Adjusting Our Ford Lehman Tachometers In Four Easy Steps

The tachometers for our Ford Lehman 120 have been a question mark since we bought the boat. We have had no way to know how accurate they are, and our cruising RPMs help to determine how much fuel we burn per hour. With the price of fuel today, this is an important piece of information and we would like to be as accurate as possible. Of course, calculating the number of hours run and the fuel added to the tank will give us an average, but we want to be more precise. Running the engine at our average cruising RPMs of about 1750 will mean a fuel burn of about 2.2 gallons per hour (GPH). Running at 1950, the fuel burn jumps up to 3.1 GPH and at 2000 RPMs, it is 3.4 GPH. Having the correct readings on the tachs can save us some considerable cash considering our cruises are usually thousands of miles.

 

I recently purchased a Digital Photo Tachometer or Optical Tachometer as they are sometimes known. These can be found from many sources online and priced from $22.94, which ours was, up to $300.00 or more. We chose the less expensive unit based on recommendations from others, and although we want the tachs to be fairly accurate, they don't have to be precise. The process is pretty simple and only took a short period of time.

The first step is to place a small piece of reflective tape that comes with the unit on the flywheel in a spot where the beam from the photo tach can easily reach it and will be convenient for the tester. It is important that any dirt or grease be cleaned off so the tape will not fly off while you are calibrating. The second step is to start the engine and let it warm up to operating temperature. This calibration can be done at the dock or while underway. I decided to do it initially at the dock and then re-check it again at some point while we were underway.

The third step is to take the actual measurements. The photo tach needs to be pointed directly at the strip of reflective tape and the beam must hit it every time the flywheel turns. A digital read out on the photo tach gives an over all average for several revolutions. I began with the engine at idle, which is about 700 RPMs for our engine. The RPMs were increased to different points and the difference between the actual tach and the photo tach reading were recorded in a notebook. I ran at 1000, 1200, 1400, 1500, 1700, 1800 and 2000 RPMs to give me a complete range. I did not test at wide open throttle. The readings were consistently 74 RPMs less at the photo tach than the actual tachometer. The tachometer at the upper helm was reading about was 125 RPMs less at the actual tachometer than the readings on the photo tach. The upper tach is the most important since we do most of the steering from the upper helm station.

Once I had the corrections to apply to the tachometers at the helm station, it was a simple matter to find the access to the small potentiometers on the back of each tachometer for the fourth and final step. These are found in very small holes usually covered by a small plastic piece that has to be pried off. Different tachs can be found in different locations but the adjustment is the same. With a small screwdriver that will fit in the tiny hole, slowly turn the adjustment one way or the other depending on whether the reading needs to go up or down until it is where you need it to be. Let the engines run for a while, and check the tachs at different RPMs until they are within acceptable readings. Our tachs run off the alternator so I know the readings will not be perfect, but fairly close. Once satisfied that all is as it should be, the engine can be shut down and everything put back where it belongs. This was probably the simplest and quickest project I have done in a long time.