I have an Lowrance Airmap 100 that I bought in 98.
I have updated the data base but never updated the system software.
I know that there has been at least two system updates since I bought
this unit because I have downloaded both to my computer but not to my GPS.
I am reluctant to do these upgrades because I don't know
what they are supposed to do.
Anyone know what is different with versions 1.8 and 1.9 from 1.7?

Thanks,