Compass Slates This is where you will find all the odd ball slates. The navigate slates are nice when you are trying to do drawings and such. The Magnetic slates are great for instructors. Johns Quick Tip’s: Slate Cleaner Every diver has a tip to clean their slate some use toothpaste, others scotch-brite pads and my personal favorite on I hear sand. There is actually a great cleaner that will last a long time. It is called a Magic Eraser they are available at most stores and used for cleaning scuffs off furniture and stuff. They are cheap and last a long, long time.