How to create an instant hurricane mooring

By Charles E. Kanter


Having watched scores of people drag anchor over the years even though they have an abundance of highly touted ground tackle while other boats hold their ground, it has become obvious to me that technique is the clue to anchoring in severe conditions.
Hurricane Erin, La Forza at hurricane mooring August 1, 1995

         We survived Hurricane Erin without a scratch while others were not so fortunate. Corinne and I had anchored our 32-foot catamaran La Forza at the head of Nigh Creek, a tributary flowing into Hopetown Harbor in the Bahamas. We had the eye of the storm pass just to the south of us, leaving us in the dangerous semicircle throughout the entire ordeal. Below are my considerations on preparations for surviving a severe storm in an anchorage, in my priority order:
         1. The number and proximity of other boats, especially unattended or charter boats -- It is other boats breaking loose from their moorings or dragging their anchors that historically are most likely to cause damage to you, to others, and to themselves. Those are the likely boats to have inadequate ground tackle and insufficient personnel to properly prepare and monitor them.
         A person who cruises extensively has long exposure and maximum opportunity to develop workable techniques. Charterers and charter boats may not share this learn-by-experience opportunity, and this was proved once again during Hurricane Erin, when the majority of boats that broke free or dragged were unattended or charter boats. Hurricane Luis did the same to Simpson Lagoon in St. Marteen when a charter company moved a fleet of fifty boats from Tortola into Simpson Lagoon trying to avoid the storm.
         2. Protection from the expected wind and wind shift -- The closer you are to the eye of the storm, the more drastic the wind shift will be. If the eye passes directly overhead, you will experience a 180-degree wind shift. Being at the correct shore of an anchorage to obtain the maximum protection from the expected winds is a learned technique.
         A radio receiver is a staunch ally, but study and understanding of how a storm works is still essential. Official and unofficial radio nets are on the air transmitting valuable storm location and wind direction data. Except in the most remote areas, there is usually a hurricane net of fellow boaters on VHF radio. During Hurricane Erin we obtained storm information on ham radio, a local VHF net, and Silbert Mills' reports from Admiral's Yacht Haven in Marsh Harbor. Silbert has a state-of-the-art satellite tracking computer system that shows the storms, and he was glad to share that information with us.
Hurricane Erin, La Forza at hurricane mooring August 1, 1995

         3. Possibility of storm surge -- During Hurricane Erin we experienced about a five-foot storm surge at the head of the creek in which we were anchored. The main harbor surged a bit higher. I suspect this was the primary factor in tearing loose so many boats from their moorings. We had sufficient scope to protect us, and by the manner in which the bridle was tied, were prepared to quickly increase scope if it became necessary.
         4. Bottom conditions and holding power -- I put the bottom last, because that will be the item you will have the least power to control. Therefore, prepare to take alternative actions. For instance, when we anchored in the creek during Hurricane Erin, had I found the creek bottom solid rock or coral, a place where no anchor can be expected to hold reliably, I was prepared to run long warps to mangrove strong points on shore or drop lines to the bottoms of dock pilings. Always drop your line to the bottom of the piling. Driven pilings are weaker than they appear, and the leverage from a line fastened near the top can easily snap them off. Being in close enough quarters to reach these secure points is a true advantage.
         5. Be the first in the anchorage and leave plenty of time to prepare -- Corinne and I moved to the head of the creek two full days before the storm hit. While others were still speculating on which way the storm might go, we were digging in for the blow. Better to have been prepared and the storm not show up than frantically lay anchors at the last minute in a compromise location. We also ran our water- maker overtime and filled every possible container in the event we were trapped in the creek after the storm and the water was contaminated.
         Sizing up the situation I determined that a good star mooring assembled from anchors was the solution. This mooring type is well known in commercial circles and is described in the Society of Naval Architects and Marine Engineers (SNAME) literature. The dredged bottom of the creek was not conducive to reliable holding; therefore, lots of scope was called for. Excessive scope has the very negative problems of allowing too much swing and exacerbating any tendency to sail on the anchor, not something you want to do, especially in a very close area. Many modern boats, especially fin-keel, spade rudder, dinghy underbody configurations are notorious for anchor sailing.
         I built a three-anchor star mooring out of my main anchor, a Delta 22, and my two FX11 Fortress anchors. The Delta, with six feet of 3/8" chain and a 5/8" rode was laid out toward the northeast, the most exposed direction and the direction from which the highest winds would come. The two Fortress anchors, each with fifteen feet of 1/4" chain and 1/2" rodes, led out at approximately 120 and 240 degrees respectively. The three anchors formed an equal angle mooring at the intersection of the three rodes and the bridle.
         The bridle consisted of one 1/2" line from the starboard bow fastened to the three anchor rodes with a rolling hitch. The three anchor rodes were fastened to a cleat on the port bow and safe-teed to a central cleat on the deck. That meant that the left side of the bridle consisted of three anchor rodes and the right side of the bridle consisted of a single 1/2" line. The length of the bridle sides were about sixteen feet, or the beam of my boat.
         At the center junction of the bridle and the three anchor rodes, I fastened a very heavy kellet (a weight sometimes called a sentinel, angel, or bouncer). I scrounged around the waterfront and found a cement block that weighed about fifty or sixty pounds. I tied it to the junction with a separate line, being careful to avoid any possibility of chafe.
         For all practical purposes, La Forza was anchored to this huge cement block, which rested on the bottom in six feet of water, and the cement block was anchored to the three-anchor star mooring. La Forza has virtually no tendency to anchor-sail, and with the scope to the kellet being 2.6:1, it prevented any possibility of anchor-sailing.
         Short scope in and of itself will moderate anchor-sailing. That is why boats have so little tendency to do it on a mooring. The mooring I constructed had not only provided very short operational scope but also was the most incredible shock absorber I have yet encountered.
These boats didn't stay put - Charles E. Kanter photo

         Before the storm reached us, my anchor rodes were protected from errant propellers because my anchor lines lay on the bottom, held there by the heavy kellet. During the storm, it was obvious that the kellet principle was what kept us from dragging. When we retrieved our anchors after the storm passed--judging by the way they were set--it seemed obvious that the kellet principle worked so well that the anchors had so little tension on them that they never dragged nor even dug in to their maximum.
         At the height of the storm there were recorded 120-knot winds. In our protected location, we were buffeted by 60- to 70-knot gusts. The kellet held the vessel weather-cocked into the wind. The lack of scope from the deck to the kellet did not allow the vessel to anchor-sail at all. La Forza would fall straight back, with no tendency to veer or fall off. As the boat fell back, we could watch the cement-block kellet rise up, but never quite get to the surface. When the gust subsided, the kellet would gently sink back to the bottom, the forward movement of the boat moderating its action.
         Time after time we would get the full brunt of the wind, but each time the forces were absorbed by this exceptional shock absorbing system. This meant that scope between the closest anchor, the Delta, and the kellet never went beyond about 10:1. Figuring that each degree beyond the Simpson-Lawrence scope design parameter of 3:1 markedly increases the holding power, it can be assumed the anchor never came close to its potential holding power.
         Previously I had experimented with a kellet made from a canvas bucket with a rock in it. At that time its main purpose was to keep my anchor rodes down to protect them from the propellers of the small boats buzzing around while anchored. Now, I am going to construct a kellet made from a two-foot length of four-inch PVC pipe with a section of chain running through it and filled with a mix of lead weights and cement. I will supplement that weight with jury rig weight or water-filled canvas buckets if needed.
         An interesting idea for those with chain rodes is to attach a canvas bag at the junction of your chain and bridle and fill it with the balance of chain from your locker. Simple, easy, and very heavy!
         For monohulls, especially those with chain rodes, a good extra-heavy duty bridle/snubber can be made using two docklines, one on either side of the bow in bridle fashion as a substitute for your usual snubber. Shackle or tie them with rolling hitches to your chain or rope rode. Do not trust an ordinary chain hook under these circumstances unless it is moused.
         Lead the lines through chafing gear fixed securely to the boat, back to your primary winches so you can adjust them without leaving the cockpit. Leave a large bight of slack in your anchor rode between the bridle attachment point and your deck cleat or samson post. Adjusting often will help lessen chafe and allow you to increase scope for tidal surge. If you have those common bow chocks (called skene chocks), you must take extraordinary preventive measures against chafe. Those chocks act like knife blades in survival conditions.
         Fasten your anti-chafe material to the boat, not to the line. A piece of two-inch vinyl pipe makes good chafe gear. Lead the lines through the pipe in order to avoid slitting them, which will destroy their effectiveness in survival conditions. That way your snubbers can stretch and contract, and you can adjust them right through the anti-chafe materials. Better still, replace those marginal chocks with good quality roller chocks and eliminate the worry altogether. Using docklines as snubbers leaves no direct chafe points between the boat and the anchor rode. Therefore, if the snubbers do chafe badly, you do not compromise your anchor rode.
         The use of a kellet is not new technology. It is ancient history, well documented in authoritative reading such as Earl Hinz's Anchoring and Mooring, Chapmans, and SNAME. My contribution to this technology is the manner in which I attached it to a three-anchor mooring and to the greater weight I used.
         There are commercial gadgets available, such as the Rode-Rider, which allows you to run a weight up and down your rode using another line. There also can be a myriad of alternatives to this system.
         Prepare now. Knowledge is the key to survival.