Why do you Need Celestial these Days of GPS?
Truly, you don’t. A boat is not required to get to Hawaii or Bermuda or take a trip round the world. Planes are much cheaper, faster, more comfortable and efficient. However, to choose a life at sea it is fundamental to be prepared to take care of yourself: to be self reliant. This is stated by Murphy’s Law which was invented on a small boat at sea. Electrical appliances are vulnerable in the salt air after a while especially in harsh weather.
Therefore, celestial is a more dependable means of navigation. Packing a hand held GPS and spare batteries in a secure vacuum sealed bag seem ideal but it is still vague. Furthermore, its dependency lies on the availability of signals which can be affected by several factors one being worldwide military conflict.
However, learning celestial is quite a rewarding venture. It makes you an expert navigator on land and on sea. Learning how to do a running fix pays of in instances where the GPS gets lost and you’re left with only one shining light or at the coast where there is only one land feature and it is not a radar target.
In celestial navigation, it is trivial to check the compass with the bearing to some celestial body, even well away from any land marks and in a strong unknown current. GPS, however, is not equipped for this nor is any other instrument aboard a sail boat or ship. Only celestial can give you a reliable compass bearing.
Finally, learning and practicing celestial navigation gives a wonderful intellectual satisfaction. It is a way to see science and math really come together and do something both tangible and useful. Learning celestial also makes you a better mariner because if you are depending on something that you cannot hope to know anything about, it makes you anxious about your navigation. (I.e. GPS, it is a black box. You can just hope and pray that it works right… and you will only really know that on the last day). When you are anxious, you are more likely to make a mistake… risk the chance of exposing your anxiety to the crew which could undermine your leadership and in turn lead to all sorts of unpleasantness.
In the long run, it is essential to learn celestial. It makes it worthwhile knowing that you are capable to navigate. It also increases your credentials helping you secure a good position on various vessels.
One last related thought: GPS is (in an abstract sense) just a version of SatNav (the Navy Transit System…now long gone) that works efficiently. In short, there have been all-weather global satellite positioning for more than 20 years yet the requirement of learning celestial from an ocean license exam was never considered to be removed by the USCG. Whatever the reasoning behind that decision, it is many-fold increased for small boats at sea.