The Promar 100' Lead Core Rope 5/16"Dia Coil is our extra heavy duty rope. Perfect for Lobster hooping or crabbing in deeper water. This rope is a high tensile strength, 5/16 inch diameter leaded rope. Because it is a heavy sinking rope, this will not float on the surface. This limits the chances of the rope getting caught in the boat prop when retrieving traps.