Normally, when we start to paint something and start a paint pot, we always aim to be clean enough to not stain the pot every time we have to wring out the brush. First, it's a nuisance because we get dirty, the boat and what's around, and second, the boat no longer closes properly and when it does it sticks to the paint.
For that reason, I have loved this solution. It is a very simple and very practical idea at the same time and only consists of crossing a rubber over the boat, as we see in the image. This way we will not touch the edges, although we will also have to do it with care. Then we remove it and the boat will be as in the beginning.