NavList:

Via the use of an artificial horizon, and shooting the sun twice, 4 hours between shots gives a good break. This method, assuming you are at the same location each shot is sort of "cheating" but it does provide a "fix". BTW, a basic hand held GPS unit will provide coordinates, latitude andlongitude, to within a few feet. These coordinates can be used to check your artificial horizon position shots. I assume you have a sextant. Nautical Almanac daily page tables work fine,a digital watch for time keeping and a helpful friend to do the record keeping is about all that you need. If pressed,you can make /keep your own notes. Likely others here are much more knowledegable than I, and could help too.

Alan