Are paper charts really necessary today?

The fact that the US Navy is going back to teaching celestial navigation at Annapolis after a 20-year hiatus provides impetus for discussion about the way we navigate so blindly using push-button electronics today.

The USS Guardian, an Avenger-class mine countermeasures ship (MCM–5), ran herself up on the Tubbataha Reefs in the Philippine Islands on January 17, 2013. The officer in charge told the navigator to trust the electronics because they were newer and updated.

An investigation eventually found the ship’s electronic charts — produced by the National Geospatial-Intelligence Agency — was inaccurate by up to 8 nautical miles. This chart was used by the crew of the Guardian, and played a significant role in the grounding. However, significant errors by the crew and commanding officers were also reported, including that they should have noted the inaccuracies in comparison to other charts.

The distance that the electronic charts used by the Navy misplaced the reef, an incredible 8nm, is roughly the distance of the horizon at sea level. Yet on the ship’s back-up paper charts, evidence of this distinct barrier was said to be crystal clear.

The upshot of this misadventure was the wreck that had to be cut up and then hauled away. The US Government also had to dip into the coffers and pay damages to their Filipino counterpart.

ELECTRONIC CHARTS
At sea, GPS and digital navigation can be accurate, assuming the fixes from the satellites are accurate, and the end user is using the Latitude and Longitude generated to pinpoint their position on a paper chart. Electronic charts, however, can also be inherently inaccurate. And there are hidden traps for the unwary.

Most chart suppliers’ disclaimers release the manufacturer from any liability surrounding the accuracy of the positions generated. But these days many boaters go to sea with only digital navigation, often little knowledge or understanding of how to fully operate their plotters properly, including such basic things as the correct magnification to ensure that they don’t hit known (otherwise hidden) obstacles.

Team Vestas Wind, a VO65 yacht racing in the Volvo Ocean Race 2014-2015, freely admitted that incorrect GPS plotter use and lack of proper chart magnification was their error when they famously smashed into the reef Cargados Carajos Shoals in the Indian Ocean.

There is also the case of another mariner leaving a Queensland harbour, who put the boat on autopilot to match his plot on the electronic chart. He cut a corner where a finger of the reef came out and tore the bottom off the boat. By zooming in he would have avoided the embarrassing call to the insurer.

PAPER CHARTS
Paper charts are not just a critical back-up in the event of loss of power. If you have no depth sounder as well, a series of plots will also let you see about tide and improve your dead reckoning exponentially.

Digital is not always accurate and there are misgivings with the technology, such as source and updates, your use of it, correct magnification, as well as the reliability of the satellites themselves, your power on board, and any cartography mistakes inherent in the source files. Please check the notes on the top of a paper chart.

Pantaenius says you should consider additional education, putting your head out the companionway, and to use Pilot Guides, Notices to Mariners, books and, absolutely, yes, paper charts.

Proper navigation is essential for you and your crew’s safety, to avoid becoming another USS Guardian or Team Vestas Wind and, at best, to avoid insurance liability. More on the insurance side of things at www.pantaenius.com.au, who prepared the bones of this story.