Over the years the screen on my old sounder got a bit scratched. Mostly salt I think, from waves splashing over the top.
Anyway, just got a new unit and decided to look for a screen protector.
Couldn't find one for a Garmin 556s and the price on other models was pretty savage.
Yesterday I was at the Good Guys and grabbed a packet of two protectors for an iPad for $15.
I can get four out of each one for the 556, just using the wife's craft guillotine to cut them.
You get a cleaning cloth and applicator card too.

Can't tell it's on there at the moment. Hopefully it'll stay that way when they hit the sun.