We marched in a pretty heavy rain storm once—weather came up fast. Once off the field we got into a dry place and had the kids and band parents dry everything off completely—we used plumes and the boosters had some hand hair dryers and they say and dried each plume carefully. One director sat with the brasses and percussion and made sure they wiped down their equipment throughly. Another sat with woodwinds and did the same, plus drying pads. We did not lose one instrument. Think about it, when playing, every wind instrument is subject to moisture. If they are not dried after each rehearsal. You will have damage