AstroNav is accurate to about 0.1 Seconds of Arc and contains a comprehensive list of stars to Magnitude 10.

The difference between a comprehensive list and the more normal, selected list is that you choose your body rather than being limited to a list. In effect a selected list is far more restrictive as you generally have to choose your stars before you take a sight.

The Almanac screen will produce a Nautical Almanac to the same standards of accuracy as the UK/ US Governments’ “The Nautical Almanac.”

Celestial data has other applications thus the Twilight screen will calculate the times of twilight for a month or passage and the Planet screen offers data over a period.

The passage plan can be used as an entirely independent check on position breaking the dependance on fully integrated navigation systems even further.