What does it indicate if the anchor chain alternates from heavy to light strain?

When the anchor chain alternates from heavy to light strain, it signifies that the anchor is not holding effectively on the bottom. This condition generally indicates that the anchor is experiencing movement, often caused by changes in tide, wind, or current. When an anchor is securely set, the strain on the chain typically remains relatively consistent, with a continuous pull that reflects the weight and tension required to keep the anchor in place.

In contrast, heavy strain may occur if the boat is trying to move against the current or wind, while light strain can indicate the anchor is dragging or not fully embedded in the seabed. This alternating strain pattern is a crucial signal for mariners to assess their anchorage situation, and it often necessitates re-evaluating the anchor's hold before the situation escalates.

Other options do not accurately reflect the dynamics of anchor performance. For instance, a heavy anchor might cause issues, but alternating strain primarily points toward inadequate holding. Meanwhile, requiring lubrication isn't a relevant factor in the context of chain strain observed; lubrication primarily pertains to maintenance and does not influence anchoring efficacy.