I was sailing at Datchet on Sunday and notice Phil Holliday was using a nifty gadget to dry the inside of his boat out without removing the patches. See the picture below.
The black box houses a fan which is attached to a modified radio pot lid. The fan is driven by the boats battery and pushes a surprising amount of air through the boat, which escapes via the breather tube and bung hole. It is a great way of avoiding the total removal of patches but I would recommend always removing part of a patch to so that moist air is not compressed into the electrics . It would be a useful device at championships to blow air through the boat between races to keep it as light as possible but again with the partial removal of a patch. I am investing in one at a cost of £12 for the fan only with 3d printed insert into the lid and £16 including the modified pot lid. One needs to add an XT30 or similar connector to the fan wires. If you are interested in acquiring one, contact email@example.com