A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Brad Morris
Date: 2018 Sep 12, 09:59 -0400
I am going to break ranks here and state that the methods of navigation used by the Polynesians would have been quite familiar to Cook and most European ship's masters when Cook visited Polynesia in the 1770s.
I would start off by saying that "Celestial Navigation" is something of a misnomer. While in theory one could navigate soley by using a succession of position fixes determined from the observation of selected celestial objects, in practice no good navigator ever should, does now, and did so even less in Cook's time. The main means of navigating should be by dead reckoning and certainly was in Cooks time. Dead reckoning involves using all the information available to maintain a running plot of position. In Cook's time, European navigators groped, smelled and tasted their way around the European coasts. They noted the colour of the water and the way the waves broke. They 'swung the lead' to take sounding of the depth of water beneath them and examined what was stuck to the tallow on the bottom of their lead weights. From all this information, and their own experience, and the knowledge that had been passed down to them from previous generations of navigators, they formed an understanding of where they were and which way they had to go to reach their destination. European navigators would have nodded sagely as his Polynesian brother would have explained how he noted the prevailing winds, ocean currents and the habbits of migratory birds. How he could smell approaching land when it was still below the horizon, feel the echoes in the water from swells bouncing off atolls and see the greenish reflection of forests on the underside of clouds.
Polynesian navigators were an elite fraternaty who also knew the year-round positions of more than 150 stars and used this knowledge to help them fix their position in their mind. Captain Cook and his elite navigators, his ship's masters, (William Bligh was one), also 'knew' (had tables of) the positions of many celestial objects and through a much more mechanical process which we now call "Celestial Navigation" used this knowledge to periodically correct the running plot of their dead reckoning position which they kept on a paper chart. I would contend that the details were different but the process of "Celestial Navigation" was actually recognisably the same in both cultures.
As for technology, the Polynesians - as far as I know - had no technology to help them make use of celestial bodies in determining their position. It was rote learning of accumulated knowledge about what the sky looked like, passed down through the generations. Their running plot of position was in their head. The European technology of celestial navigation used by Cook had advanced to a state that it was essentially mature. From then on, sextants, clocks (until the 1950s anyway), ephemerides, sight reduction tables and all the other paraphenalia of "Celestial Navigation" were produced at what was essentially the cutting edge of 18th century technology and did not - have not - improved significantly.