Correspondence: Dolphin -Pole Navigation

As a kid, I always enjoyed rowing about Kenosha Harbor when it was foggy. This recreation became especially challenging late in the season, as the density of the fog often approached that of pea soup. I soon discovered that if I came upon a dolphin pole, I could determine direction and location from the slip number tag (always positioned on the same side of the pole and numbered in sequence). And I could get to any place in the Harbor by striking out from that point. This method worked, even though I often couldn’t see anything except the dolphin pole and tag number. I soon traced a harbor map on the aft seat of my small craft to aid in my newly discovered navigation skill. Distances in the Harbor were short enough so a compass wasn’t even required. I would simply observe the trailing wake and use that to ensure progress in the proper direction.

Many years later, it was a natural extension of this childhood-discovered technique to use the Go To function of loran and GPS and get quick fixes on marine positions. It was an easy task to enter the lat/long location of the “printed center of a compass rose,” as if it were a dolphin pole, and with the Go To function, work the problem in reverse.

So for years I have used the latitude and longitude of the center of compass roses as printed on nautical charts as known waypoints, first with loran and now with GPS. This gives me known positions on the chart with the direction roses in place, centered over the waypoint. Naming and entering the lat/long of these waypoints in my GPS, I simply hit the Go To button and enter the name of the waypoint. The GPS returns a direction and distance to the specific waypoint. I now draw a line from the direction indicated through the center of the specified rose and out the opposite side, 180° from the direction given. I am on that line. Furthermore, I am the “GPS returned distance” from the center of that compass rose. It is a very simple, quick way to determine and plot position, and it works well with local nautical charts.

As a result of my experience using this method, I have, on numerous occasions, tried to get nautical charts published with the lat/long of the center of the printed compass roses included with each rose. But to no avail.

Steve Mulich of Minneapolis sails in the ocean, Gulf, Med and Great Lakes.

By Ocean Navigator