Another common requirement is a place to attach to. As a result, seaweeds are commonly found near the shore. Within that area, they are found more often on rocky shores than on sand or shingle. Seaweeds occupy a wide range of ecological niches. The highest elevation is only wetted by the tops of sea spray, the lowest is several meters deep. In some areas, seaweeds near the shore can extend several miles out to sea. The limit to how much they grow in such cases is based on how much sunlight there is. The deepest living seaweeds are the various kelps.