TL;DR: To navigate using an astrolabe and a watch, measure the sun’s altitude at local noon with the astrolabe. Adjust for the sun’s declination from an almanac. Your latitude is roughly the corrected sun altitude. For longitude, compare local noon to the reference time on your watch; every hour difference equals 15 degrees of longitude. This method involves basic trigonometry for calculating angles and positions but is quite approximate and not highly accurate for longitude.
This allows to navigate beyond the horizon from the coast so you can travel overseas and beyond where other people has been on a ship without following the coast.
I mean they did have decently good mathematicians abord the ships who were already great mappers. An accurate time peice would help with accuracy… But nautical maps were nautical maps. More accurate ones are great but they did already have serviceable ones.
What’s wild about the cultural concept of your average maps of the period in a more general sense is they were often more conceptually philosophic and religious tools meant to illustrate a “you are here” for the soul. Geographic accuracy was at best a secondary consideration.
This whole post assumes you can derive some pretty advanced trigonometry from scratch.
TL;DR: To navigate using an astrolabe and a watch, measure the sun’s altitude at local noon with the astrolabe. Adjust for the sun’s declination from an almanac. Your latitude is roughly the corrected sun altitude. For longitude, compare local noon to the reference time on your watch; every hour difference equals 15 degrees of longitude. This method involves basic trigonometry for calculating angles and positions but is quite approximate and not highly accurate for longitude.
This allows to navigate beyond the horizon from the coast so you can travel overseas and beyond where other people has been on a ship without following the coast.
I mean they did have decently good mathematicians abord the ships who were already great mappers. An accurate time peice would help with accuracy… But nautical maps were nautical maps. More accurate ones are great but they did already have serviceable ones.
What’s wild about the cultural concept of your average maps of the period in a more general sense is they were often more conceptually philosophic and religious tools meant to illustrate a “you are here” for the soul. Geographic accuracy was at best a secondary consideration.
But it is me going back right? So as long as I revise before the trip, it should be fine.