Are charts really necessary?

The answer depends upon the type of boating you do and where you do it. On some lakes and in familiar waters not far from shore, where you can reliably see landmarks, some boaters don't use a chart (or there isn't a chart available). If you travel out of sight of shore, or away from home waters, or operate at night, you need charts. You'll have to decide if a handheld device that has GPS and integral electronic charts (such as a GPS unit, a tablet, or a smart phone) is sufficient for safe navigation where you operate. Basic considerations are the size of the screen and its readability in daylight, the battery life, and the water resistance of the device. Read articles about how handheld devices can be used - it's an evolving technology that may be suitable for some boaters. If you travel away from familiar waters, GPS and either a chart plotter or paper charts is still the way to go for now, with the new technology as a backup.