Last week, loyal readers may recall, I described the pitfalls of global positioning systems, particularly when users who follow them with blind faith rather than common sense can suffer tragic consequences.

     My diatribe had been provoked by the sad tale of a Canadian couple whose GPS led them to drive their van off the main highway and onto a dirt road in Nevada’s high desert, where they got stuck in snow and mud. The woman survived for seven weeks on candy, trail mix and creek water before being rescued by hunters; crews are still searching for her husband, who left on foot to get help. 

    This week, in the time-honored journalistic practice of self-contradiction, I take an entirely different position and extol the benefits of GPS, which my kayaking partner, Ian Frenkel, and I employed during the Essex River Race in Massachusetts last Saturday.

    This 5.5-plus- mile competition along the narrow, winding Essex River from Route 133 in Essex, through marshes and out behind the barrier beaches of Ipswich and back, attracts more than a hundred paddlers and rowers in a wide variety of vessels, including Banks dories, multi-oars gigs, sliding- and fixed-seat shells, single and double kayaks, surfskis and paddle boards. The boats go off in separate divisions, with slower ones getting a head start.

     Since Ian and I would be paddling a tandem kayak, one of the faster classes, we started in the next-to-last heat and waited in our 22-foot boat while race officials started the other competitors amid shouts and cheers from spectators on shore.

     When they finally called our division to the line Ian set the GPS and handed it to me in the stern cockpit. I looped its lanyard through a bungee cord on deck, propped the device against a combing so I could read the numbers and pressed the “Enter” button. We jockeyed for position with other boats, including one that slid directly in front of us, forcing us to move to a new spot seconds before the starting horn sounded.

     “… 3, 2, 1 – Go!”

     While we flailed away I focused on the GPS speedometer. It quickly surged from 3 mph to 4, then 5, 6, 7 …

     “Ian! We’re up to 7.6!” I shouted.

     Our goal had been to average about 6 mph, and I didn’t want to burn out in the first 100 yards. But the tide had begun to ebb, which gave us a decent boost, so I wasn’t too concerned about the fast pace. Also, we had another goal – to win – and a rival boat was right on our tail.

     In fact, it was drafting us – a maneuver that allows paddlers in a following vessel to keep up while using only about 75 percent of the energy.

     “Hang on, Ian, I’m about to take some evasive maneuvers,” I called. As the stern paddler I control the kayak’s direction with foot pedals connected to a rudder, and I pressed hard with my left foot. Our kayak swerved sharply to port.

     I glanced over my shoulder. Our competitor had quickly adjusted his course, so I stomped starboard, then port, then starboard again in a series of fishtails. At last he lost our slipstream.

     “Let’s punch it!” I shouted, and we sprinted another 20 strokes to build up a lead.

     “I think we lost them,” I said, glimpsing behind.

    After a mile of steady paddling we began to close on the Banks dories, which had started a few minutes ahead of us.

    These classic wooden vessels, used as traditional fishing boats starting in the 1850s on the Grand Banks of Newfoundland, had been built in numerous shipyards in and around Essex. They remain popular as workboats and tenders. With long overhangs at both ends to ride over big waves, Banks dories are designed more for stability than speed, but happily for us, the seas and wind were calm Saturday – unlike last year’s race when 30 mph gusts buffeted the competitors.

     Continuing to rocket along at 7-plus mph, Ian and I also began passing fixed-seat rowing shells, and we exchanged friendly nods with most of them as we swept by. The one exception was a rower who began to drift across our path.

     “Head right!’” Ian urged, and I swerved.

     What the …? The rower continued to steer in front of us.

     “Hey!” I cried, but it was too late – his oar smacked into the bow of our kayak and wound up in Ian’s lap.

     The unsportsmanlike response would have been to snatch the oar and heave it far from the rower’s boat, but Ian simply pushed it aside and we resumed our quest.

       About this time the river meandered through a series of S-turns, and I momentarily blundered by trying to cut a tangent instead of sticking to the channel.

      The GPS instantly informed me of my error, showing that our speed had slackened in shallow water.

      “Damn! We’re down under 6!” I steered back to the deeper channel and watched the GPS climb back over 7. After rounding the halfway mark at Cross Island and beginning to paddle back upriver to the finish line, though, we began bucking a strengthening ebb tide.

       The GPS showed our speed slowed to 5.5, with the average pace dipping by a tenth of a mph every few minutes.

      With less than a half-mile to go we were down to a 6.1 mph average.

      “Come on! Let’s kick it in!”

    Ian buried his paddle and we grunted and gasped the last two minutes. As we crossed the line I glanced one final time at the GPS: 6.0.

     Our time was 56 minutes and 2 seconds – good enough for first place in the tandem division.

    “Now it’s on to Blackburn!” Ian said.

    In July we will return to the celebrated Blackburn Challenge, a 20-mile open-water race around Cape Ann near Gloucester, to defend our championship earned in last year’s race. No rest for the weary.

     Come to think of it, we didn’t use a GPS then, nor did we use one while winning our class in the Mayor’s Cup 28-miler around Manhattan last year.

      Hmmm.

      Oh well, at least we didn’t get stuck in the mud and have to live on trail mix for seven weeks.