Hi. When the copper coat, impregnated in the gel coat, wore out on our Parker 21, we move to International's UNO and have stayed with it ever since. After a season there is hardly any weed growth and just an occasional barnacle. We since changed from a Parker 21 based on a trailer to a Parker 275 on a drying mooring. As instructed, we use one coat all over then add a light second around the water line. And that's all you need to get good results. According to the experts, eroding anti foul like Uno should not be used on a drying mooring. Well, it works fine on the river Hamble.
I can't remember the maximum time between painting and launching. In practice you paint all the accessible parts and let those dry. For the parts that are obscured by the trailer or cradle or chocks, there are different ways to slap paint on those parts just before you launch. Don't worry, the paint does not wash off. If you are being craned in, chances are that the straps will expose the parts you could not reach before. Otherwise I have found success using two trolley jacks. Place a stout piece of wood laterally across the hull then two stout uprights under it either side of the centre line, each resting on a jack. Then gently raise the two jacks in parallel and up goes the hull. Paint the areas that were previously covered by your supports. It is quick and easy. If you don't do all your painting on one go, keep your brush soft by sealing it in a plastic bag and placing it in a freezer. Happy painting!
Ken Surplice
Commodore