Whether you're sailing down the river or taking on the open seas, it's important for every boat owner to take care of their vessel. With the Harbormaster boat cover, you can confidently rely on the most heavy-duty materials to protect your boat from weather, water, wear, and animals. The 300 denier polyester construction is water repellant and helps to fend off nasty mildew. Use the tie-down rope and shock cord to secure the cover on all sides of your boat.