Why would you not be able to navigate using the celestial bodies on a flat Earth?
So you are prepared to assert that o the Flat Earth
each degree north or south of the equator represents very close to 111.2 km in distance and
each degree east or west of the Greenwich at the equator represents very close to 111.3 km in distance.
Otherwise, those navigators would get very confused.
They did not get very confused, so I can only assume that you are, once again, full of it.
Yes, but all those navigators knew that they were navigating a globe where
each degree north or south of the equator represents very close to 111.2 km in distance and
each degree east or west of the Greenwich at the equator represents very close to 111.3 km in distance.
Even "the Wiki" agrees with the first part.
Latitude
To locate your latitude on the Flat Earth, it's important to know the following fact: The degrees of the Earth's Latitude are based upon the angle of the sun in the sky at noon equinox.
That's why 0˚ N/S sits on the equator where the sun is directly overhead, and why 90˚ N/S sits at the poles where the sun is at a right angle to the observer. At 45 North or South from the equator, the sun will sit at an angle 45˚ in the sky. The angle of the sun past zenith is our latitude.
Knowing that as you recede North or South from the equator at equinox, the sun will descend at a pace of one degree per 69.5 miles, we can even derive our distance from the equator based upon the position of the sun in the sky.
From Finding your Latitude and Longitude
Now, 69.5 miles is not exactly 111.2 km, but it is close and 111.2 km is a bit more accurate.
As to "each degree east or west of the Greenwich at the equator" representing "very close to 111.3 km in distance" we do have
Longitude
To find your longitude you just need to know how many hours apart you are from Greenwich, UK and a vertical stick to know when the sun is at its zenith over your present location.
Now "the Wiki" does not explicitly say that each degree of longitude is 111.3 km in distance, so we have to look to other sources.
Geographical mile
The geographical mile is a unit of length determined by 1 minute of arc along the Earth's equator. For the 1924 International Spheroid this equalled 1855.4 metres.
. . . . . . . .
In any standard, the length of a degree of longitude at the equator is thus exactly 60 geographical miles.
From
So one degree of longitude at the equator is
60 x 1855.4 metres or 111.3 km.
Do you want to reconsider who is confused?