Sphenoid bone - internal view There are four main parts to the sphenoid bone: the body (corpus), the lesser and greater wings (alae minores et majores) and the pterygoid processes. The body is the most centrally positioned portion. Anteriorly it contributes to the nasal cavity, laterally it builds the medial wall of the optic canal.
The anchor you chose will depend on the type of anchoring you do. Cruising anchors are larger plow or claw anchors capable of holding boats to various bottoms. Kedging, Forfjord and Workboat anchors are used on commercial vessels.
Well first of all it's not an anchor. It isn't used to hold your boat in one position or tie it to the bottom. It is a device that you trail off the back end of the boat while at sea. It helps keep the boat pointed into the waves or wind, after you've taken the sails down.