I came across an interesting article in a sailing magazine the other day. They reported on some research done by a University on changes in situational awareness by users of chart plotters compared to users of paper charts. They gathered data during controlled sea trials as well as on a simulator, so this isn't just the typical "survey".
Their research indicated that long-term users of chart plotters changed the way they perceived things and that that affected their situational awareness in ways that appeared irreversible (they were no longer able to switch to the way the looked at things before on short notice).
One experiment they did was to let people navigate they way they are used to and later ask them to draw a chart from memory. They found that people using chart plotters basically only recalled their route and way points, but not the general layout of the sailing area.
They also let people plan a trip in the usual way, and then forced them to navigate by sight and memory alone (no charts or plotters). This was done on the simulator, because in real life it would have lead to groundings...
Overall,they concluded that experience counts (more experienced sailors did better) but that to get the best benefit of digital navigation you had to have the most experience using other means of navigation. Something along those lines.
I mostly sail in familiar waters where I don't need to "navigate"; the GPS I use serves to record where I was and to tell me how fast I am going, rather than where I'm at. However, when I go further afield, I tend to look up paper charts (or online versions of paper charts) and use them to plan routes and familiarize myself with local conditions.
The few times I've sailed with chart plotters would support anecdotally the results of the research.
There's a tendency to have one's attention totally sucked into the device and to reduce navigation to lining up the blue line with the red or green dot (or whatever the colors).
Sailing with someone who used a chart plotter and acted as my navigator, I averted two groundings by using landmarks and observations to override steering commands based on plotted course, had one grounding when I didn't act quickly enough (I thought the course we were steering was retracing a track from the way we came a day before, but instead it turned out to be a saved track from a year ago - in an area of shifting sand banks. I was fooled into trusting bad data.)
At another occasion, I observed the owner of one boat, with chart plotter, sailing into a big wind hole, because he (and his navigator) were too focused on their waypoints to carefully observe how the successful competition skirted the hole by sailing close under the land.
Finally, I've seen at least one person using a plotter lose track of where North was (in addition to being disoriented to where we were).
How are you navigating?