Final answer:
A buoyant heaving line must exhibit enough buoyancy to support a particular weight, abiding by Archimedes' principle, to meet Small Vessel Regulations. It ensures the vessel can carry a significant load without the risk of sinking.
Step-by-step explanation:
In order for a buoyant heaving line to meet the requirements in the Small Vessel Regulations and be approved for use on your pleasure craft, it must exhibit sufficient buoyancy to support a particular weight in water. The concept relates to Archimedes' principle, which states that the upward buoyant force exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces. In the context provided, the maximum buoyant force being ten times the weight of the steel indicates that the vessel can handle a substantial load without risk of sinking. It can carry a load that is nine times its own weight as the buoyant force will support the combined weight of the vessel and the load.
The narrative provided describes a tense situation at sea where a dinghy, experiencing rough conditions, is being expertly navigated to avoid being capsized by the waves. This scenario underscores the need for having reliable safety equipment like a buoyant heaving line, which could be critical in a rescue operation.