| 摘要 |
<p>The underwater mooring for small boats comprises a cylindrical bar with a fin running round it in a spiral, and which is screwed into the seabed. It can have a ring at the top for mooring, and for engagement when screwing or un-screwing, and can be moved to another position or left in situ as desired, e.g. when the boat is hauled up onto dry land for maintenance. The anchor can be carried by one person and emplaced at a marl soil.</p> |
