charts ? droid vs computer

[thataway]

I'll answer my own question--the Phil Endecott Topo maps for the i pad are for the most part excellent. Some areas have better scans than others, but for example the Lake Powell basin are excellent. Some of the Keys are just good. You can load, and erase topo maps at will, to avoid loading up the I pad--and can overlay the street or google maps.

The Spaglass is a fairly complicated program, but certainly useful. It uses the base maps in the i phone or i pad, but does not seem to use the topo maps that I can find either in the excellent PDF guide or by experimenting with the program. Think of it as a very sophisticated hand bearing compass, when laid flat horizontally, the base map of the i phone takes over form the camera. It also is useful in astronomical use, and could be used as an emergency sextant. I have not tried the math functions, but it appears you could use it for navigation (assuming that you have tables etc).

Both good additions to the i phone (I have an i pad 1, and don't think it would be of as much use there lacking a camera.)