magickal offerings
Sea Witches typically collect items from the shore (seaweed, sand, shells, etc.). Since everything in nature is imbued with energy, it is generally considered polite to return the energy taken when these items are collected. This can be done as an offering left at the water’s edge: something you made, a silver coin, a sprig of your favourite herb, a strand of your hair, or something personally meaningful.

Just be certain that it will not be harmful to the environment in which it is offered, and of course, don’t leave trash or plastic wrappings behind.