The lake I sail the most (Lake Perris, southern CA), like many others, is justifiably worried about importation of Quagga mussels
and other exotic pest species (present in the lakes of the Colorado River, not too far away). These have microscopic larvae, so the only way to be sure not to bring them is to be coming from waters not infested, or have the boat completely dry. The park inspects entering boats, their principle criterion being dryness. I also had my boat inspected on the road driving in Idaho. So I have to be sure my boat is completely dry, even if the last place I sailed was the same lake.
Mostly this is straightforward: open the drain plug, open the hatches for air, stick some towelling on a stick down the mast and rod holder sockets. The toughest place to get turned out to be the seat post holes, especially after I modified them to take the twist lock seat posts. These are narrow enough that not much evaporation occurs in the little puddle of water, and are difficult to get a corner of towel in to sop it up.
My solution was wicks, made from cellulose sponge, as shown. I just put them in the holes when I park, and, in my climate, soon thereafter the water is gone and the wicks are dry.
I have noticed, however, that there is wet we never get. For example, if you screw out the bungie holders on the amas, the bottom of the holes are wet, and probably always are. There must be a ton of such places (some of them holding seawater next to metal and silently corroding parts of the boat
). Another seems to be the mast, which I sometimes see drip water long after taking the boat off the water. I only hope there is little enough back and forth water transfer to make transit of exotics unlikely. In my case, I'm mostly in this lake or the Pacific, so little chance, but I do plan to visit the Colorado River.