GPS navigation software installed on the small boat sailor's iPhone might make all the difference between a safe return to port or a distress call for assistance.
Entering a dense fog-bank brings doubt and consternation to the crew as the far-off coastline quickly fades away, and soon nearby buoys and beacons marking dangerous offshore shoals are swallowed up too.
It's time for the skipper to pull out the iPhone from the waterproof bag to access GPS navigation software for help with a safe return to home port.
GPS Navigation Software and the iPhone
"Navigation was always a difficult art, though with only one ship and one bell." (Lewis Carroll, The Hunting of the Snark, Fit 1)
The iPhone comes with two built-in essentials, that used in combination, make it a serious tool for offshore and coastal navigation if plotting is done on official nautical charts. Those two essentials are:
- The built-in GPS receiver itself
- A magnetometer compass believed to be much improved on the iPhone 4G, with a claimed (though not proven) accuracy of up to two degrees provided certain user guidance is followed).
GPS Navigation Software – Electronic Chart Systems for the iPhone
"He had bought a large map representing the sea, without the least vestige of land." (The Hunting of the Snark, Fit 2)
Most small boat owners will probably find it more convenient to download an electronic chart system (ECS) rather than attempt manual position plotting in cramped working conditions on board (but they should keep in mind the cautionary advice at the end of this article).
One of the most user-friendly yet feature-laden GPS navigation software Apps for the iPhone (and iPad too) is provided by Navionics, whose electronic chart systems can be purchased separately according to the desired region, and downloaded at Apple's iTunes Store. These charts have world-wide coverage, and once installed are available for off-line reference.
Another supplier offering iPhone access to GPS navigation software, all in one complete App, is iNavX which is also available at the iTunes Store and its inclusive price may appeal, although world coverage is not quite as wide.
According to MarineLink.com, iNavX is able to access Navionics charts too (as long as they have been installed) by those who require its coverage, perhaps of some specific area, and who don't mind the expense.
Both these Apps require just the internal GPS in order to show the user's position on its electronic charts, but of course the iPhone may also use additional signals from WiFi and/or cellular if they are available.
Electronic Chart Systems – Basic Features
- Zooming and panning to reveal detail on the chart
- Current GPS position at the centre of display
- 'Course Up' indication with the 3GS iPhone
- Heading vector displays direction of heading (if speed greater than 5 kts)
- Search facility for POI, marinas, tides and currents
- Tide or current stations in vicinity listed with height of tide, times of sunset and sunrise
- Tracks followed can be saved and shared with friends by Email or Facebook
- 'Waypoint' voyage planning function
- Range and bearing from the user's GPS position to some other point
GPS Navigation Software and the iPhone – Cautionary Words
Such remarkable 'bells and whistles' may lead one to believe that these vest-pocket wizards have taken over the marine field of play from authorized government charts, and publications including the important Notices to Mariners, but that is not the case.
The wise user will regard the iPhone laden with GPS navigation software simply as an aid to navigation and will assess the information it presents with due caution, remembering always that the sea can be a hard taskmaster.
Reference
Institute of Navigation Newsletter, Spring 2010 Edition, "GNSS Udates", (pp 14) and "Consumer Markets & the A-GPS Revolution", Dr. Frank van Diggele (pp 3)
George Backwell - Merely a reporter who endeavors to provide a reliable compass for those who look for one.
