Boat electronics represent a big investment, so it pays to take care of them.
Many multifunction displays (MFDs) have a touch-screen interface, but all those pinches, swipes, and taps can leave the screen with a plethora of fingerprints and dirt that needs to be periodically cleaned off.
While it may be tempting to reach for the Windex or other glass cleaner, these can do more harm than good.
Glass cleaners contain ammonia, and while this may remove fingerprints, it can, over time, damage the underlying screen layer, leading to a cloudy or milky-white screen that can be difficult to see, making those expensive electronics all but useless.
Nearly every manufacturer says the best thing for screen cleaning is a little water and a clean microfiber cloth — no fancy chemicals or additives required.
Distilled water is best as it's free of impurities. For a clean spot-free shine, just spritz the screen with a little water and wipe carefully with a clean microfiber cloth.
I keep a small spraybottle in a drawer close to the nav station specifically for this purpose — 2 or 3 ounces of water lasts a whole season.
For best results turn off the display and allow it to cool for several minutes prior to cleaning, this is especially important if you have had backlighting turned up to full brightness.