SEAL THE COIL COVER
Here is a good tip I got from one of the online forums. If you have ever tried taking the coil cover off a Minelab coil for cleaning, you know what a task it is, to do without breaking something. So to keep the dirt and salt water from getting between your cover and coil, try taking a tube of silicone caulking, either the clear or white, and running a generous bead around the edge of the coil cover. If you ever need to replace the cover, the silicone will cut open easily with a razor blade or small knife.