I have 2 HDS_7 on my boat, never remove them. haven't had a problem sense Christmas 09. wash my boat at the car wash and the units get washed as well. some one earlier said they have trouble removing the face covers, from the Lowrance HDS-8 units. they are hard to remove, here is what I do, and it makes it so easy. use a paint bucket lid remover, and the little hook on the end of it, will hook behind the face plate. and just pull it off. makes it very easy.