More on navigating systems
April 21st 2007 21:42
More on Navigation systems.
People can get hung up on charts and reading them. Lots of wiggly lines and not much meaning to it all at first glance. So they stay away in droves. Compass? Yes we used one once when we were in the guides or scouts. Don’t know much more than that and its too hard to work out the variation, deviation and stuff like that. The compass has been helping man navigate the oceans and lands for hundreds of years. It is not hard and you don’t have to abide by all the rules as long as you make up some that work for you.
Did you know that the bigger the ship the more sophisticated it’s navigation gear the more it has to carry the very basics of navigation. As mentioned in yesterday’s blog it is the law. Paper charts that are updated every time a change is made or a modification is noted. A compass that is swung on a regular basis and checked every four hour watch and every course change as well as a compass log being kept. That is as well as a gyrocompass that does not need magnetic needles or cards. Gyros have been around for years and have allowed ships to steer within one degree of accuracy and they also are used to drive auto pilots and radar plotters. The most elementary of depth sounders is the lead line and if the sounder goes kaput then that is what the ship must resort to. This is easy for the recreational boater to copy, just a good piece of string around a fishing handline holder with a decent lead weight and marked off in metres. How can that break down?
Each watch on a ship the compass is checked with an azimuth bearing or even with a sextant! What you cry, that old piece of outdated technology. It is still as capable of helpkopkp0[p
ou navigate across the oceans with out breaking down as reliably as your pencil and piece of paper is still the most accurate and cheapest way to jot down a message, despite emails, sms and dare I say telephones. The sextant is a piece of equipment that does not break down, needs no battery, has no magnetic variation and has only the slightest amount of error which can be easily rectified or accounted for. It can afford to get wet, as can your paper charts (to a degree) and your compass and lead line.
I am not saying chuck out your wizz bang gadgetry, it is after all so accurate and user friendly but please look at the alternatives and learn how to use them as you do need to keep them on board.
Tomorrow; depth and speed to navigate?
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