Designed for the specific demands of anglers targeting the largest tropical species. RIO's Leviathan lines have been specifically designed for the largest of tropical species. Each line features a powerful front taper to cast the biggest of flies, and a short, heavy head to load blue water rods. The 250gr Leviathan line is built on a 35lb core, while the 300gr to 400gr lines are built on ocean-tough, strong cores in excess of 50lbs. All Leviathan lines of 500gr and more have ultra-strong cores of 70lbs and more, that will easily battle large fish and resist being cut on coral and rock structures. A hard, tropical coating prevents the line from wilting in the heat.