Don't do a radio check on 16.
And most of all, don't tell everybody your business on 16 like, "I just got a new VHF and I just want to see if it works," or, "this is the first time I've used my radio since last summer and I just want to see if it works." First of all, we're not supposed to do radio checks on 16 for many reasons, mostly involving safety and even search and rescue. Secondly, if you're doing a radio check, everybody out there knows that you want to see if the thing works.
Don't return that stuff you borrowed last season from your friend who has the boat in the next slip at the marina.
He's probably forgotten who he lent it to. And if you return it he's going to miss the fun of going to buy it again. And worse still, if you return it, you won't have it anymore and you're going to have to go to buy replacements.
Don't knock down all the wasps' nests that have been constructed under every out-of-the-way part of the boat.
Learn to live with them. They can bring you luck, like when that thief who comes on the boat doesn't know where the nests are hidden.
Don't demolish the cute little nests of the field mice who have made a home in the boat in which they can make babies.
You'll have some ready made bait which will save you money for the fish that you won't (or maybe will) catch. And if those cute mice make their home under the cowling of your outboard you'll have mystery roasted hors d'oeuvres
Sun damages not only your skin but also your eyes. Protect yourself all over.