SATELITES ARE FOR THE BIRDS – However much the world of navigation becomes more detailed and easier to understand, the accuracy created by modern systems has not actually improved much since the first days of exploration.
Yes, we crave the accuracy of DGPS systems that can tell you to a few yards exactly where you are, but spare a thought for those who set out thinking the world was flat.
Roman scholar Claudius Ptolemaeus (more commonly known as Ptolemy) created the original system of latitude and longitude back in the second century. Later, in the 1500s, Magellan circumnavigated the globe, a journey that took 3 years, and arrived back in Spain albeit a day later than expected. On arriving home a difference of one day was noted, thus creating the international dateline.
Of course, the stars were found to be very useful for working out where you were on the high seas, and today we still need to understand how to define position using the planets, moon, sun and stars. In fact celestial navigation by using a sextant and book after book of tables called almanacs is still a must for the dedicated skipper.
Modern technology has taken us beyond the stars. With the advent of wide area augmentation systems (w.a.a.s.) and global positioning devices (g.p.s.), navigational tools are abundant for the modern boater. It was Dr Getting (the phrase “getting there “ springs to mind), back in the late 1950s , who invented the system of satellites required to make these units work effectively and today we can, at a push of a button, know exactly where we are to within a few feet.
Garmin, Raytheon and Magellan among others produce a range of gadgets, from huge TV screens to wrist watches, and every marine store carries a selection to suit every budget. No more guess work, no more wondering where you caught the best fish, or even how to get home – units accept hundreds of way points to pinpoint favourite locations and most systems also have ‘track back’ technology to get you home safely.
A gps unit can now give you speed, distance, direction, position and bearing as well as many other features; interface with your vhf radio and send messages to coastguard or other boaters; control your autopilot; work with your fishfinder and even act as a security device to locate your boat – add cameras to make it a 24/7 surveillance system.
Yes, you still need paper charts for plotting, but while you interface your chartplotter with your radar and your autopilot allowing you to almost sit back and enjoy the ride, spare a thought for Noah who had to rely upon the birds to find land.