Naviguessing, a thing of the past
Originally published by The Lookout Newspaper, on 29 August 2022, this article is reproduced here in its unedited state.
When a ship travels the seven seas it racks up the sea miles, a distance measured in nautical miles. A nautical mile is exactly 6,076 feet. For simplicity’s sake, sailors just say it is 6000 feet, or 2000 yards, and as a Chief Radar Instructor once told me that’s close enough for government work.
An important nautical measurement is a cable, which is one-tenth of a nautical mile, or 200 yards. In the Stan Rogers classic sea shanty Barrett’s Privateers, an unofficial anthem for many Canadian sailors, the Antelope chased an American ship until, “at length they stood two cables away.” That’s 400 yards for all the flat-faced civvies out there. Unfortunately, 400 yards seemed to be the operational range of an American cannon, resulting in disaster for the Antelope.
The person who knows the distance the ship has traveled is the Navigating Officer, abbreviated Nav O, and informally known as the navigator. It wasn’t long ago that we kindly referred to this person as the navi-guesser, since the ship’s position was based on a series of best guesses, comprised of dead reckoning and navigational fixes, some of which may have been cocked hats, a flawed navigational fix comprised of three bearing lines that do not meet, and the occasional basket of eggs, an astronomical fix comprised of a collection of circles, occurring when the sun is directly overhead.
Dead reckoning is a method of determining a vessel’s current position by combining the last known position with the vessel’s speed, elapsed time, and course steered. Originally, dead was spelled “ded,” for “deduced.” Today, even the most basic cell phone is GPS enabled, allowing you to immediately know the distance and direction to the nearest Tim Hortons. Dead reckoning a ship’s position is now a thing of the past, as every HMC ship is fitted with GPS-enabled computer-based navigation systems and electronic charts.
Important to the safe navigation of any naval vessel is the depth of the water below the ship. There is nothing more dangerous than running aground, touching bottom, or sustaining propeller damage. Charts give historical depths, but many coastal waterways and harbours have bottoms that may shift with the currents. The ship has an echo sounder that broadcasts a sound wave and measures the current depth of the water below the hull in meters, feet or fathoms, a fathom being a measurement of six feet.
Before echo sounders, a member of the ship’s crew would lower a hand lead line, a slender line with a lead weight. When the lead weight struck bottom, markings on the line would indicate the depth of the water. After reporting the depth to the bridge, they would raise the line and perform the measurement again in a few minutes, or as soon as required by command. There were times when the sailor would not raise the line completely, and let it drift in the water before making the next measurement. This was known as swinging the lead and considered to be the lazy way to perform this duty.
Today, a lazy sailor is sometimes said to be swinging the lead, or more directly might be referred to as skiving. For some sailors, skiving is considered an art, and they pride themselves in their ability to skive.
You will find over 4000 examples of Jackspeak in my book Jackspeak of the Royal Canadian Navy (2nd ed.).