When is an anchor considered 'up and down'?

An anchor is considered 'up and down' when the crown of the anchor rests directly on the bottom. This position indicates that the anchor is properly set and holding, allowing it to effectively secure the vessel in place. When the crown is on the bottom, the anchor is in a balanced vertical position, and its flukes are likely engaged in the seabed, providing the necessary grip against the forces of wind and current.

The other scenarios described do not represent the anchor being in an 'up and down' position. If the anchor is raised, it is not deployed and cannot perform its function. When the anchor is clamped, this usually refers to a situation where it is prevented from falling freely, again meaning it is not in the optimal position. A slack chain suggests there is no tension, which could mean the anchor is not securely holding the vessel, and the anchor may not be properly set. Therefore, the correct answer highlights the ideal state for effective anchoring while the other options indicate situations where the anchor would not be effectively securing the vessel.