Sea magick is magick involving the element of Water, usually performed at the seashore. If you do not live on the coast, this type of magick is quite flexible, so your local lake, river, pond, or bathtub will work in a pinch. Even placing a bowl of salt water on your altar, with the proper intentions, is sufficient for performing sea magick.
What kinds of spells can one do with sea magick? Any type, but the materials used (spell components) will be sea-related. With a little reworking, a pinch of sea salt works in place of regular salt, and the types of seaweed and shells available constitute entire languages of their own.
There are several types of magick that are usually associated with sea magick. Since most precipitation is water-related, weather magick is a form of sea magick. In earlier days, sea witches were expected to control the weather for seafarers so they could have a safe voyage. Moon magick is another type of sea magick, as the Moon controls the sea’s tides. Mirror magick is a little-practiced derivation of moon magick, and is also considered a form of sea magick.