I've done that for sunglasses, cell phones(still have the sucker-crackberrys are indestructible), keys (both boat and car), wallets, flashlights, fuel filler cap when I didn't know the chain was broken... although most of my stuff ends up in the drink because of my own carelessness, not drinking-since I'm generally skipper, I wont drink. Unfortunately our waters, while warm are never that clear
and if you haven't done all that and ran aground you haven't been on your boat long enough.
Does getting caught in the current where the stern of the boat gets pulled upstream while beaching on an island and having the skeg plant into the sand count?
Haven't lost sunglasses, yet. But I bought a $30 pair of Bomber glasses that are lined with foam so they float. Towels and hats seem to be common objects I end up handing over to the lake beds.