Clean water, hard sun.
Different problem than Spokane.
Lake Coeur d'Alene and Lake Pend Oreille have soft, low-mineral water. You don't get the same hard
water spotting we see across the Spokane River. What you do get is more direct UV. Long days from
Memorial Day through Labor Day. Boats sitting in slips with the sun on the dark hull from dawn to
evening.
For wakeboats and inboards that live on Lake CDA through summer — Mastercraft, Malibu, Centurion,
Supreme — the sun and the constant on-off-water cycle is what wears the gelcoat. For lake-home boats
on Hayden Lake or Priest Lake, the issue is more often algae and waterline staining from sitting at
the dock for stretches.
For a slip-kept boat on Lake Coeur d'Alene, plan on a buff and wax every other season with a
maintenance wax mid-summer. For a lake-home boat used most weekends, the same cadence usually works.