The recent hurricanes in Florida have provided a severe test of dock and mooring systems. I have a 27-foot Island Packet sailboat moored in the Indian River about five miles south of Cocoa, Fla. The boat and mooring have survived near-direct hits from hurricanes Charley, Francis and Jeanne. Our dock, on the other hand, was completely destroyed.
I am convinced that a properly designed mooring system is the safest alternative in severe weather. Wind velocities during Francis exceeded 64 knots from three quadrants for a duration of about 15 hours. The maximum gust recorded at the nearby Merritt Island Airport was 78 knots. The wind velocity from Jeanne was about the same but for a shorter duration.
This mooring system consists of a 250-lb mushroom anchor set in firm sand in about 7 feet of water. Seventy feet of 1/2-inch chain extends through a mooring buoy to the boat. A 5/8-inch swivel is set about 1 foot off the bottom. The mooring buoy is positioned 12 feet from the boat. The 1/2-inch chain is connected directly to the two bow cleats on the boat by running the chain through the port chock, sliding through the port cleat with a 90° bend and shackling it to the starboard cleat. The chain eliminates chafe, which was the most serious problem during the long durations of these storms. This system provides a normal scope ratio of about 7:1 and a minimum storm ratio of about 5:1 during storm surge.
The boat has not suffered any damage at all during these storms. I checked the anchor and chain after Francis and Jeanne, and found the anchor completely buried and the chain with no kinks or tangles. All components of this mooring system are U.S. manufactured. Each component must be of the highest quality, since failure of any single item means failure of the entire system. I recommend using the heaviest chain possible and not decreasing the chain size from the mooring buoy to the boat. A single chain connected to two or more cleats on the boat eliminates tangles from a harness and spreads the load between the cleats. The mooring is entirely made up of chain, which eliminates chafe and provides security from vandalism. This system allows me to move the boat from the dock to the mooring in August and leave it for the duration of the hurricane season until November.
John Allis is a water resources engineer living in Colorado Springs. In addition to his 27-foot Island Packet cutter in Florida, he sails a 19-foot Mariner sloop in Colorado.
