Anquet – tide by tide

…and a phone to steer her by

Mobiles have had a bad press as navigational tools, but if I were forced to choose one single piece of electronics to take to sea it would be my phone. That’s not a popular view among professionals.

Instructors, coastguards and rescue services learn of many cases where boat owners, especially of powerful motor yachts and RIBs, set off for the open sea with nothing beyond a chart app on a mobile phone, and no knowledge of the underlying skills needed to navigate safely. For the Royal Yachting Association, mobiles are well down the list of recommended priorities, because of the risk that they will be used badly. Textbooks give stern warnings that you must not use them for navigation.

Satellite accuracy on a mobile

How accurate is the position calculated by your smartphone? The Royal Institute of Navigation is sceptical. Its new book on electronic navigation for leisure sailors says: “At sea, mobile phone positioning uncertainty will typically be several hundred meters or more, which may be enough to put us into danger”.

I am looking for some proper studies on this issue, because I am sceptical about that statement. In the meantime it’s easy to check what your phone tells you about its own location performance when it relies only on satellite signals.