Electronic charts are not foolproof
February 25, 2013
the rocks may be great for scotch, but it’s bad for boats. On Jan. 17, the USS Guardian, a Navy minesweeper, hit a
reef in the Philippines.
Navy said the electronic charts used on the Guardian
had an error in the reef’s charted location. The investigation will
probably reveal other issues regarding the ship’s navigation and watchstanding.
The error was supposedly introduced when the chart makers digitized the chart. The
ship is a total loss and the Navy has said it intends to cut the 1,312-ton Guardian up to be barged off and scrapped.
“bump and go” river sand groundings aren’t necessarily a big deal. That’s unless
you bump the rocks the Corp of Engineers have been blasting away on the
Mississippi River. Ground your vessel on less forgiving bottoms like reefs and
wrecks, and you’ll be in trouble.
blog is more for the salt water and big fresh water mariners. Still, all
mariners find that poor navigation and lax watchstanding is often the root of
errors can have their seeds in false confidence and overreliance on a single system
or means used to fix your position. No one source should be used for
navigation. Navigational accuracy and your proximity to dangers would then completely
depend on that sole system. Electronic navigation systems are not infallible. Relying
only on GPS and chart plotters as the color video version of God’s given truth can
be dangerous. The waterfall of electronic charts bores you into a wicked
complacency. You forget that the wheelhouse has windows.
rocket science advertises a GPS margin of error of several tens of meters,
including holes in coverage. Overlay that on a paper chart from Captain Cook’s
era, circa 1775, which are perhaps the most recent charts for the waters around the Tubbataha
Reef where the Guardian got stranded, and you are standing into danger.
around the wheelhouse. You’ll probably see two radars, two GPSes, a pair of
VHFs, an AIS, a fathometer, a chart plotter, electronic charts and hopefully paper
charts. These are even seen on some river towboats. Add windows and binoculars,
and don’t forget the Coast Guard’s required publications.
are a lot of tools that can be used for situational awareness in comparing
tracks, fixes, and positions. Use them all. If you are running a routine route
and think you know the chart like the back of your hand, you are on a fool’s
errand. Ferry and tour boat operators keep learning that the hard way — shoals
change, buoys move, new wrecks pop up.
all the advances in navigational equipment, there still is not an electronic
version of common sense.
Editor's note: The Navy contracted the DP crane vessel
on Friday as salvage work on the Guardian began. Using its DP system, the Jascon 25 can position its crane within reach of the Guardian without requiring mooring equipment that could damage the reef.
out an interview with Adm. Cecil Haney on the Armed Forces Network after he met
with the crew of the Guardian at
Sasebo Naval Base in Japan.