app4sail vs Celestial Navigator

Nautical navigation app. uses free S57 vector charts Not everywhere in the world those maps are available and not all of the available maps are implemented at this moment. Instead you can use maps of the project 'Openstreetmap'

Celestial Navigation Calculator with - perpetual Almanac - star finder chart with animation. Use phone sensor for altitude. - calculation of lines of position ( intercept/delta ) - celestial object data - meridian passage calculation - running fix support - astronomical position calculations with two or more altitude observations - Hipparchus 150 star catalog - World chart with lines and position Program can be set to use device's sensors (gyro, compass) to position the star finder chart in real time. Capture celestial object approximate altitude. Correct Altitude with a Marine Sextant reading (not included). You still need a marine sextant to do celestial navigation, but the phone sensors may be used for training. Software for iPhone and iPad, with the same features. e-book with manual and celestial navigation tutorial.