Originally Posted by Seeratlas
For thousands of years men have plied the seas,,,only in the last what, 30 or so have they gone nuts on all this available instrumentation
Seer, in his post, just reminded me of when I was a cadet and sailed aboard an old steam turbine cargo vessel. She was a beaut. Traditional in every sense of the word. Huge funnel, teak decks cambered so you had to hold on even in port, coal-burning galley and enough brass to overshadow any ship in the "Queen's navy". Did I know about that brass? Polishing it all was a job for the cadets!
Anway, to my point. The ship's navigational equipment consisted of:
1 standard, magnetic compass
1 steering compass, also magnetic
1 radio DF
1 very old radar (valve set) which was worth more as a curio than navigational hardware
1 towed rotator logg (Walker's)
corrected charts, tables etc.
All very basic stuff and a lot less than the average small yacht has these days but with no more kit than this that 9,000 ton ship had ploughed the seas between Europe and New Zealand / Australia / Far East for something like 25 years and never a misshap. Why no groundings? My theory is it was because the ship's navigators never knew exactly, to the nearest foot or metre, where they were and they were therefore duly cautious.
The REAL DANGER arrises when navigators of ships big and small are over confident and exactly sure of their position. We have all heard them, "The GPS says we are there so we are precisely there" they state as they point at the position they penciled in on the chart only to find later (and I hope not the hard way) that they made a mistake in transfering the position. Or maybe they are using a plotter and the chart is neither up-to-date nor ECDIS approved and there is a little but oh so very hard rock not shown.
Ponder also the fact that many of the charts we use today are the result of surveys made 100 years or more ago when the surveyors, who did a magnificent job, were plotting positions using horizontal sextant angles and station plotters. The charts latitude and longitude can also be out by a cable or two thus needing a GPS position to be adjusted to the chart's grid. Even today in well surveyed areas with heavy shipping we find discrepancies creeping in. For example, the position of Vinga lighthouse at the approaches to Gothenburg (Scandinavia's biggest port) differs between Swedish and Danish charts by about 200 metres.
As always, I am not knocking technology I am simply pointing out that a good navigator uses all available aids to navigation to establish his / her position but is also cautious.
Aye // Stephen