Features June 2004 Issue

Headings: Navigation, Then and Now

Between Marion-Bermuda and Newport-Bermuda events, June 18 will mark Nick Nicholson's 18th race to the Onion Patch, and his 25th year as an offshore navigator. In this article, he compares the racing navigator's role and methods in 1979 with those in 2004.

The year 1979 was my first in offshore racing, but it was also the tail-end of an era. Except for races such as Marion-Bermuda, in which only celestial navigation could be used, the classic methods of offshore navigation were just about to disappear. 

A hand-held radio direction finder passed for state of the art navigation electronics in 1979.

Texas Instruments introduced its revolutionary TI 9000 Loran-C navigator in 1978—at a price of $2,100—and the age of true electronic offshore navigation was just beginning. For me in 1979, however, electronic position fixes were a year away. Instead, my tools were sextant, timepiece, sight reduction tables, crude knotmeter, and radio direction finder. We had a plastic swimming pool thermometer to dip into a bucket of sea water to try to figure out when we were in the Gulf Stream. We looked at the sky and barometer to try to forecast the weather, and we weren't very good at it.

The daily navigation routine in those early Marion races—weather permitting—would be demanding and exhausting: Sunlines morning, noon, and afternoon; evening and morning stars if you were up to it. Sight reduction took me hours a day, and I was often reduced to working sights out lying on my back, as poring over sight reduction tables in rough weather would make almost anyone seasick.

If weather was rough or the horizon obscured, you depended on dead-reckoning based on dubious speed instrumentation to keep you headed in the right direction. Good logkeeping was critical to maintaining dead reckoning between fixes.

As you approached Bermuda, you dug out the hand-held radio direction finder (RDF), and took a dubious bearing on those Morse code blips from the foredeck, pointing the boat towards that ambiguous null in the signal.

The last 24 hours of any race to Bermuda were anxious for the navigator. All the self-doubts about what you had done for the last three or four days piled up at once: Were my sights accurate? Do I really have a clue?

The first time Bermuda popped up in front of the boat approximately when and where it was supposed to be, it was divine revelation. There was meaning to the universe. The celestial clock was still God's timepiece, and it still ran with eternal perfection. I was hooked on racing to Bermuda, and I still am.

That Was Then, This is Now
Do modern navigation aids make Bermuda Race navigation simpler? Let's look at what's involved in the navigator's preparation for the 2004 Newport-Bermuda Race aboard Richie Shulman's Temptress, an IMX 45.

Gulf Stream. In early April, I began receiving weekly Gulf Stream reports from Jenifer Clark, the Godmother of the Gulf Stream for Bermuda racers since 1980. (See Practical Sailor's May 15 article on Weather Forecasting.) These consist of a current color-enhanced infrared satellite photo of the Gulf Stream and surrounding waters, and a simplified black and white plot of the key features. High-resolution satellite thermal imagery defines the Stream—to the eyes of a professional like Jenifer—as clearly as an aerial photograph of an inland river wandering through marshland.

But I also check her thermal images against radar altimetry images of the Stream from Delft University in Holland. Using a European satellite system, these are derived by measuring differences in sea surface height between still and moving waters, and are another way of tracking the wanderings of the Gulf Stream. 

 

By the time we leave for Bermuda on June 18, I will have reduced the latest Gulf Stream picture into a series of gridded transparencies that can be overlaid on my paper chart. Yes, I still use a paper chart as a basic plotting tool, since it allows me to keep the Big Picture in front of me at all times, no matter what happens on the computer screen. The Gulf Stream will be as well-defined for us as modern technology can make it. The Stream is no longer the mystery of the Bermuda Race; it is a basic tool.

Weather. Gulf Stream knowledge without weather information is useless. Thanks to the Internet, I have been tracking weather systems for weeks, looking for patterns and anomalies that might give us an edge when the time comes to interpret an ambiguous weather forecast.

That will continue during the race, thanks to Internet access via satellite phone as well as more traditional tools like weather maps downloaded to the computer via SSB. Weather forecasting is an imprecise art, particularly during an ocean race, and getting it right is critical. The information is available to all, but the analytical tools come down to the brains on board.

Radar. With radars becoming lighter and more energy efficient, you would think that the only decision for a Bermuda racer would be which radar to carry. In fact, one of our first decisions was to eliminate radar entirely, for a single reason: weight and windage.

While this might seem completely at odds with our critical call to keep the radar aboard for last year's fog-bound Marblehead-Halifax Race on the same boat, the decision process for this year was identical: Would the radar pay its own way for the weight and windage penalty it exacted? Were we likely to get to the Bermuda finish line more quickly with or without radar? Going to Halifax, with the last 100 miles of the race often shrouded in dense fog, radar was critical in helping us locate the finish line. Going to Bermuda, the finish is more likely to be in brilliant sunshine or luminous starshine. So the radar stays home.

Computer System. Some form of on-board computer system is at the heart of navigation aboard every well-equipped offshore racer or cruiser. Yes, every self-contained component—from performance instruments to GPS receivers—has its own internal, job-specific computing capabilities, but you usually need some centralized computer to tie it all together.

This is particularly true in the offshore racing yacht, which in the interest of minimizing the number of stand-alone pieces may integrate virtual instrument displays, chart plotting, radar display, routing, and weather analysis into a single large computer screen. The risk, of course, is that a single electronic glitch could render the boat blind, deaf, and dumb electronically.

Many racers and cruisers carry laptop computers, which are cheap, powerful, have big displays, and are easily replaced. Generally speaking, however, they are a serious compromise whether racing or cruising.

Laptops are notoriously susceptible to impact and water damage. The guts of the machine lie under the keyboard, and a single dose of salt water at the nav station can turn your machine into a pile of junk. Somehow, you have to secure the laptop to the top of the chart table, making it difficult to open the table or use it for normal navigation. Then there are all those connecting wires—power supply, interconnects to inputs and outputs—that turn the chart table into a rat's nest.

A few years ago, aboard an earlier Temptress, we had custom, compact computers built into the nav station to function as a main brain. But these were heavy, power-hungry, fairly bulky, and expensive. Now, you can buy ultra-compact, powerful computers assembled specifically for mobile use. These are just a tiny bit larger than a portable CD player, but are available with the computing power and connectivity of a current-model laptop.

The advantages of these small machines are obvious. They can be mounted in protected, out-of-the-way locations, with all connections out of sight. You can combine them with a permanently mounted display that fits your nav station and budget. You can use a throw-away wireless keyboard and mouse, which take up little room on the chart table and are easily and cheaply replaced if damaged. These computers separate out the guts of a conventional laptop into self-contained components that can be individually upgraded or replaced over time.

Computers of this type include two models from Argonaut Computer (www.argonautcomputer.com). These range in price from about $2,200 to $3,300, depending on the degree of sophistication. At the top end you get all the functionality of a high-end laptop, with an all-up weight of about 4.5 pounds. The computers feature shock-mounted components and anti-corrosion coating of internal components, and are designed specifically for use on boats. Aboard the current Temptress we use an ultra-light Cappuccino computer, weighing less than two pounds. This is a popular computer for racing boats, where light weight is more of a consideration than marinization or the fastest processor speed. The Cappuccino TX3 sells for about $1,300, including operating system, wireless keyboard, and other goodies—everything but the display and marine software. See www.cappuccinopc.com.

The drop in the prices of TFT flat screens means that you can have a large, high-quality permanently mounted display at the nav station, with the decision based primarily on the available space. For belowdecks installation, the ability to dim the screen at night is more important than the ultra-brightness of a daylight-viewable display. A 15" screen, such as the Sony aboard Temptress, is the smallest you want to consider for chart plotting, given their low price in today's market.

Charting. We have run Nobeltec's Visual Navigation Suite for years. For a Bermuda race, charting software is only important near the start and finish, but it can be worth its weight in gold at those points. This is particularly true on the approach to Bermuda at night, when the fastest course to the finish frequently skirts dangerous reefs gut-wrenchingly close, and you can't see the bottom the way you can in daylight. See www.nobeltec.com.

Of course, we also still plot our position on the old DMA 5161 Newport to Bermuda chart. It's pretty hard to draw the Gulf Stream on your chart plotter, but it's a piece of cake on a paper chart.

Performance Instruments. It is in the realm of performance instrumentation that the divergence between cruisers and racers really shows. You can spend as little as $1,400 (plus installation) for a basic, networked speed/depth/wind/heading system such as the Nexus Network System 3000. In contrast, a full-bore Ockam grand-prix system such as the one aboard many state-of-the-art racers (and some cruisers), including Temptress, can cost $30,000 before installation.

It is really, however, an apples and oranges comparison, for the Ockam system includes performance functions designed specifically for racing, such as race course setup and data logging functions, that are of no more than academic interest to cruisers.

 

During any race, I set up a virtual instrument panel on the computer screen, and run constant strip charts on wind speed and wind direction over time, which are critical for weather forecasting and deciphering wind oscillation patterns. These charts also allow you to monitor real boat performance compared to polar predictions, to determine if the boat is being sailed efficiently.

Instruments must be calibrated properly for their output to mean anything, so we spend a lot of time before the race calibrating and recalibrating wind, boatspeed, and heading functions. If you're a racer and don't have confidence in your instruments, you might as well go home.

An integrated water temperature sensor—its output tracked on another strip chart—enables us to know exactly when we are in the Gulf Stream, even without reference to the GPS to see the effect of current.

GPS. Ironically, the core of our navigation system is a GPS design that is now a decade old. The Northstar 951 GPS aboard Temptress is virtually identical to the 941XD model we put aboard Calypso in 1996 before taking off around the world. It has proven reliable, user-friendly, and bulletproof over the years. Of particular concern for a race to Bermuda, the GPS lets you immediately see the effect of Gulf Stream currents by comparing speed over ground and course over ground with boatspeed and course steered.

We also carry a handheld GPS receiver for backup in the case of electrical or instrument failure, as the GPS is the single most important navigation tool on the boat.

SSB. The Newport-Bermuda Race still requires SSB radio for emergency communications and position reporting. This technology has changed only incrementally in decades, and has benefited only marginally from the trend towards component miniaturization.

Because it adds nothing to the weight of the installation, we will also install weatherfax software on the computer for SSB reception of weatherfax charts as a backup in case Internet access to weather charts via the satellite phone breaks down. Yes, even in the days of e-mailed weather GRIB files (a form of access that is not, incidentally, legal for the Newport-Bermuda Race, although the same files may be accessed directly from publicly available websites), there are those of us who like to see the weather coming towards us in a form that allows us to generate our own weather forecasts.

For Temptress, the old heavy fiberglass whip SSB antennas or insulated backstay antennas are yesterday's news. Thanks to Hall Rigging, our new lightweight synthetic backstay also incorporates an imbedded SSB antenna wire. Some things do change.

Internet Access. Bermuda is only 650 miles off the US coast, and the Globalstar satellite telephone system works all the way to the finish line. Race rules allow access to websites that are not password-protected or subscription services, and many competitors—including Temptress—will use the Globalstar system for Internet access to weather information.

Since most websites are not optimized for slow-speed satphone connections, this will be both more tedious and costly than accessing the same information from your home computer. The exception will be weather GRIB files, which are dramatically chopped and optimized for transmission via slow connections.

Routing Software. It may seem like a little bit of magic, but it works: Not so long ago, the Bermuda navigator divided the race into three components: the section between the starting line and the entrance to the Gulf Stream, the crossing of the Stream, and from the Stream exit to the finish. He or she incorporated the weather forecast, pre-race charts of Gulf Stream currents, and a reasonable understanding of boat performance, into a crude exercise in the integral calculus: minimize the time between start and finish using weather, Gulf Stream, and boat performance. Now, this can be done in a more systematic fashion using routing software, such as the MaxSea software used aboard Temptress.

Central to routing software are polar performance diagrams derived from a velocity prediction program. The VPP predicts boatspeed at different wind angles and velocities, and for, example, calculates optimum jibing angles downwind, and optimum wind angles and boatspeeds upwind. You use them to compare the way the boat is actually being sailed at a given moment to the way it should be sailed, as well as in helping determine the fastest angle to the finish.

To the boat's speed matrix must be added other layers of complexity: the direction and velocity of currents, and the predicted direction and velocity of winds. This is hard enough to integrate on a day-racing course, but it can be amazingly complex on a 650-mile race that includes rapidly moving weather systems and the powerful current of the Gulf Stream.

By inputting boat performance, weather, and current data, routing software tests the huge array of possible solutions to come up with the one route that works best for your boat on the race course.

Because Gulf Stream characteristics change relatively slowly—and in reasonably predictable fashion—a good Gulf Stream current snapshot, converted to a gridded binary file before the start, can serve as adequate input for the 48 hours or so between the start of a Bermuda Race and exit from the Gulf Stream.

The movement of weather features, however, can be less predictable, and daily updates of weather forecasts—once again using publicly-available GRIB files downloaded from Internet websites—need to be plugged into the dynamic weather routing program to keep the routing accurate.

This will be our second race to Bermuda using MaxSea software, and we intend to give a more detailed report on its performance later. Based on our experience so far, we can say that in common with other highly specialized software written by and for the technically oriented, routing software, including MaxSea, has a steep learning curve, and is not always blessed with an intuitive interface. It can also yield race-winning strategies when properly applied and thoroughly understood.

Log Keeping. Whether racing or cruising, we still use the same paper log system that PS reader Fred Honigman developed back in 1983. While we have lost contact with Fred over the years, his log form has kept us company for some 50,000 miles of sailing. The paper log—entered hourly when racing, less frequently when cruising—becomes your permanent record of any trip, and instantly ends arguments over how hard it was blowing, and from what direction, during the 1984 Bermuda race or your crossing of the Indian Ocean in 2001.

Combined with your sextant—which we no longer carry for ocean racing (too heavy)—the paper log and the chart that goes with it provide the ultimate backup when the fancy electronics go on holiday.

Conclusion
So...has navigating a racing boat to Bermuda gotten easier, or more difficult in the last 25 years? The most basic problem—finding that little spec of land in the middle of the ocean—is infinitely easier, thanks to GPS. The sweating palms and tumultuous stomach that used to mark the last 24 hours of a race to Bermuda are gone. But the incredible amount of information that today's racing navigator must process has, if anything, made the workload greater. The emphasis has shifted. Now, we expect the boat to be in exactly the right place, and sailed with 100% efficiency, 100% of the time, and we have the computational tools to make it happen.

Do I miss the days of sextant and timepiece? You bet. Am I proud of the way I used to do it? Of course— there's nothing quite like a three-star fix that falls into a perfect, tiny cocked hat. Would I give up my modern navigation tools on a race to Bermuda to repeat that feeling? No way, José.

 

Comments (0)

Be the first to comment on this post using the section below.

New to Practical Sailor?
Register for Free!

Already Registered?
Log In