I store my boat in a yard that abuts the tidal flats of the Merrimack River, where it is exposed to winds out of the northeast. We get some really nasty weather that the grommets on my tarp cannot handle. After purchasing too many new tarps, I developed a better system. Now I simply slide a tennis ball under the tarp, give it a twist and then tie the lines around the base of the ball. The twist takes the slack out of the tarp, provides an effective tie-in point and almost eliminates flapping. I'm amazed at how simple, strong and effective this system is.