Lesssons in celestial navigation have been reinstated at the Naval Academy in Annapolis, nearly twenty years after the subject was dropped. The move is motivated by fears that the GPS satellite system could be hacked or shut down, and the realisation that modern ships do not have a backup if GPS is lost.

In an interview with the Maryland-based newspaper, the Capital Gazette, Commander Ryan Rogers, deputy chairman of the academy’s Department of Seamanship and Navigation, explained:

‘We went away from celestial navigation because computers are great. The problem is, there’s no backup. There’s about 10 years when the Navy didn’t teach to celestial. New lieutenants, they don’t have that instruction.’

The Global Positioning System (GPS) is based on a network of 31 satellites launched in the 1990s. By 1995, the system was accurate to within a few feet and by 1998, the Annapolis Naval Academy had stopped teaching celestial navigation in detail.

‘A skilled celestial navigator may calculate locations to within 1.5 miles. Using GPS, you’re within feet. You’re not even in the same ballpark. If you can use GPS, it’s just so much more accurate,’ Rogers said.

However, if a ship were to lose GPS capabilities from a lighting strike, or the ‘cyber vulnerabilities’ of GPS were exploited, ships or even whole forces could be lost and disabled.

The reinstatement of a celestial navigation syllabus is expected to be implemented in autumn 2016. Captain Timothy Tisch at the US Merchant Marine Academy in Kings Point, where celestial navigation is still taught, has helped to rebuild the syllabus for the US Naval Academy. In a statement, he said:

‘Knowledge of celestial navigation in the GPS era provides a solid back-up form of navigation in the event GPS becomes unreliable for whatever reason. It is also good professional practice to use one navigational system to verify the accuracy of another.’

The new curriculum will, however, not enable US Navy midshipmen to navigate by the stars, as it only contains three hours of instruction. It aims initially only to give an awareness of the principles of navigating by the stars.

BBC Newsnight will be reporting on the issue tonight (Thursday 15 October 2015) and Evan Davies will be interviewing Yachting Monthly contributor Tom Cunliffe at 2230.