I haven't used MGRS, but UTM IS based on a 1000M grid. If you look at the newer metric USGS maps, the grids are printed on them.

In any event, my point was that UTM has a "finer mesh" than 1000th of a degree, but that is not especially useful using nautical charts or anything else based on a LAT/LON basis

: Doug,

: I think you are one place off. If I remember correctly UTM (Universal
: Transverse Mercator) and MGRS (Military Grid Reference System) are very
: similar. MGRS divides the globe into 10km grids. People refer to 6,8, and
: 10 digit MGRS which define 100m, 10m, and 1m squares respectively. In
: other words, 10 digits gives you 5 each for 'northing' and 'easting'. I
: think 0,0 would be the south west corner of a grid. This one I forget
: sometimes. Anyway, my GPS (Garmin 12) provides MGRS in 10 digits as an
: option. When I was testing the other night my estimated position error
: (EPE) was displayed as 17'. I switched to MGRS and the last position
: varied by no more than 4 (4 meters) for several minutes. This agrees
: fairly well with a 17' EPE.

: Tim