Many or most computer-based navigation programs, and all chart-plotters use vector charts. While vector charts have advantages -- one major disadvantage is that when you zoom out, the program doesn't display as much detail (to declutter the screen and keep it readable). Small, but very immovable hazards may not be displayed!

People who set up routes with these tools tend to zoom out when setting up routes between waypoints, especially when the waypoints are far from each other. This can cause them to set a route that crosses a hazard.

I had a close call a few years ago -- was following a route (I had set up in Nobeltec) about a mile offshore, and suddenly saw boulders barely awash about 100 feet to the side of the boat! Operator error! I was just lucky that time.

Now I use raster charts on the PC, and check routes against paper charts if I don't know the area. If I set up a route on the PC (now using Coastal Explorer) I zoom all the way in and audit the route screen-by-screen. I generally keep the chart-plotter zoomed-in enough to get the most possible detail while underway.