NavList:

Steve,

There is no difference.  People ( navigators ) like minutes because one minute is one nautical mile.  Thats it.

Note that no navigator uses seconds - they are converted into decimal minutes in the NA and on the sextant dial.  Different groups of folk use different units because they are convient, not because there are more accurate,  The US Army uses mils when firing their big guns, computer geeks use radians to compute, etc. etc.

I write my own computer programs to do nav and always use decimal degrees.  When I get an answer I either drop off the decimal part - azimuth - or multiply by sixty to get miles.  No sweat because I use a calculator.  If I was on a sailing ship in the 19th. C. then that one multiplaction would be enough to make me use degrees and minutes.

Call it tradition.      John H.