 "Amphianthus dohrnii" was at one time common in both the Mediterranean and the English Channel, but it seems now to be absent from the former and increasingly rare in the latter.In British waters, the sea fan "Eunicella verrucosa" has declined, possibly being damaged by dredging or in association with higher sea temperatures, and the already rare "Amphianthus dohrnii" has become scarcer.Prismatic compass

A prismatic compass is a navigation and surveying instrument which is extensively used to find out the bearing of the traversing and included angles between them, waypoints (an endpoint of the lcourse) and direction.