Interestingly, I have lots of paper charts onboard, and the office has loads of them, some dating back to the early 1950s. Now, how accurate are those charts? Keep in mind that most of those charts were generated long before GPS plotters were even available. Many have never been updated, but those are the same charts that are scanned into your GPS/Plotter system.
Here's where the fun comes in. Last fall, while cruising down the ICW there were times when you would enter an area that was nothing more than a dredged ditch between two creeks, rivers, etc... It's a straight line down the chart that has no entrances, exits, turns, etc... Easy to navigate without any aids other than your eyesight. Yep, just stay in the middle, keep an ear out for the depth finder alarm and you should be just fine.
Glancing at the GPS/Plotter, however, could send shivers down your spine. There were several locations where the GPS/Plotter clearly shows the boat 50 to 100-feet away from the actual position, riding on dry land. Whoops! How could that be?
A quick call to one of my old contacts at USGS provided me with the information. Those dredged ditches along the ICW were sometimes on the charts before the ditch was actually dredged. And, in some instances, the actual dredging may have been done 100-feet away from the charted location. Consequently, your highly accurate GPS is right on the money when it comes to your actual position, but the waterway on the chart may NOT be accurately depicted.
Same holds true with buoy numbers, buoy and day marker positions, charted channel depths, and charted landmarks. Buoys get moved, day markers get broken off, channels fill in, and some landmarks are now blocked by new buildings and towering trees. None of this information would be on your current charts, and it may be years before you see a Notice to Mariners report of the changes.
So, before the advent of highly accurate, electronic, navigation devices everyone, including this old man, was highly dependent upon our charting skills, compass, eyesight, and of course, utilizing the best tool - common sense. Despite this, we usually were able to eventually find our way to a distant destination, or find our way home. Sometimes, however, I, for one, wondered where in the Hell I was, but I was usually able to determine my approximate position and work from there.
Now, I know exactly where I'm at, which unfortunately, is sitting in front of this damned computer and typing this post. I wish I could go out sailing, but the wind's howling at 35 from the northwest, which has driven the water out of the entire upper Chesapeake Bay to the point that all of the boats in our marina are sitting in the mud. Maybe things will improve tomorrow. Sure hope so.
BTW: Aaron, glad to see you posting again. And, I sure miss being in the Keys.