Had my M15 out on the Ches. Bay for several days a couple of weeks ago. Still was 60s and 70s high temps there. In the morning, I'd don the life jacket and swimsuit and crawl down the ladder into the water for an early morning wake-self-up-fast swim. Not warm but not frigid either. While in the water, with sponge in hand and one hand grasping the top of the gunwale for support, I'd do a circuit or two of the boat, scrubbing the hull as I went around. Reaching under the boat I could scrub at least halfway to the other side, or at least to where the centerboard receiver lay. Took about 10 minutes and got an invigorating swim in at same time. When I pulled out at the end of the trip, a few minutes after parking the boat and trailer, I got a pail full of freshwater from the boat ramp, and with the same sponge, and a towel, gave the boat a once-over again. I'd do one side with a pail full, then dump that pail and refill it once more from the boat ramp for doing the other side. Took about 15 minutes and I wouldn't have to worry about scrubbing the boat again, till the next trip.