Re: Free or low cost GPS navigation software?
I have a Garmin 441(and paper charts!) but also have the Navionics app for my Android phone. Both have the same level of detail as the paper charts.
The funny thing is the Navionics app which cost $10 is way more accurate than the Garmin which cost ~$400. I think the Navionics app is using the cell toowers as well as the phone's GPS to resolve location. The phone can tell me which side of the slip I am on whereas the Garmin has me "near" the marina.
I agree with the others that you should use a depth sounder for monitoring depth, not the charts or chart plotter. Once while sailing with dead depth sounder, I actually grounded three miles off shore in what was supposed to be deep water according to the chartplotter. After being towed in I reviewed what happened and found that I had the chart plotter zoomed out so a series of shallows was not displayed. Had the depth sounder been working I would have noticed something wasn't right and possibly avoided a few thousand dollars of damage.