Strap Down Boats Stored Ashore

People who have watched boats in hurricanes stored ashore on jack stands say the boats are constantly being rocked back and forth, ever so slightly. Over time, the movement can work the jack stands that support the hulls out of position, which results in the boat falling over. In major hurricanes, at least a few of the boats stored ashore at every marina have been blown over. And at some marinas, almost all of the boats stored ashore have been toppled over. While boats ashore tend to suffer less damage in hurricanes than boats stored in the water, the extent of the damage ashore remains significant—broken bulkheads, smashed hulls and, on sailboats, bent masts.

Granada, Hurricane Ivan

In the past few hurricanes, a technique emerged that promises to minimize damage from boats being blown over: Strap them to the ground. Doug Hillman at Sebastian River Marina calls securing boats to the ground in high winds “common sense.” Scott Watson at Indiantown Marina says they always secure boats to the ground whenever they’re stored ashore. He estimates that in Wilma, Frances and Jeanne, the technique reduced the number of boats that were blown over by two-thirds. The same was true of boats at Puerto del Rey Marina in Puerto Rico, Swan Point Marina in North Carolina and at the Hinckley Company Marina in Florida. As Watson said, “Securing boats to the ground damn sure helps.”

The straps accomplish several things. First, they hold the boat more securely against the jack stands, steadying the boat so that there is less movement and less chance of the jack stands working loose. Second, if a jack stand were to topple over, straps will sometimes keep the boat upright or, depending on how the boat is secured, at least soften the impact by providing some restraint as the hull falls over.

The idea of strapping boats down in hurricanes seems to have arisen spontaneously at several different marinas, from Florida to North Carolina to Puerto Rico. While the idea is the same, no two techniques are exactly alike. Different marinas use different anchors and different straps, with some of the techniques being more sophisticated than others. All have their advantages and disadvantages.


Helical Anchors Screwed into the Ground — Swan Point Marina, Sneads Ferry, North Carolina and Indiantown Marina on the St. Lucie Waterway, Florida

Betty Myrick said her husband got the idea from mobile homes: anchors that screw into the ground to provide stability in high winds. He bought the anchors at a local hardware store, screwed them in by hand, and then used straps from a flatbed trailer to secure the boat. Other people at the marina, which houses 80% powerboats, liked the idea and soon it was being widely copied. Before Hurricane Floyd, Myrick said a man came by with a gas-powered drill that put the anchors in quicker and with far less effort. It was crude but it worked. All of the boats with straps and anchors held; others that weren’t supported were blown over.

Indiantown Marina

Like Swan Point, Indiantown Marina uses screw anchors that are drilled into the ground. Unlike Swan Point, Indiantown Marina houses predominantly sailboats, which have deeper keels so that boats ashore sit up higher and are more vulnerable in high winds. Scott Watson, Indiantown’s owner, said they use 4-foot helical anchors with round eyes, which are set into the ground using a posthole digger. He says it takes two men 10 - 15 minutes to install a helix. Boats are then secured with 10,000-lb. ratchet straps, which he says have very little stretch.

With anchors that screw into the ground, holding power is dependent on the density of the soil. Royce Randlett, who is president of Helix Moorings Inc., a company in Maine that sells helical anchors primarily for moorings, says any soil—no matter how loosely packed—offers at least some resistance and helps secure the boat. Randlett says they buried an anchor in loosely packed “sugar sand” in the Florida Keys and found that a 5 ½-foot screw anchor had 2,600 lbs. of resistance.

Watson says the anchors at Indiantown are secured into typical “Florida sandy soil” and notes that the longer the anchor has been embedded in the soil, the more holding power it seems to provide. The marina includes two straps per stored boat and will supply more for a fee—$30 per anchor and another $20 for the strap.

The marina was especially hard hit by Wilma and 33 of its 506 boats ashore were blown over when anchors were pulled out. Several other boats lost jack stands but, thanks to the straps, stayed upright. How many boats would have been blown over without the straps? Watson has no way of knowing for certain, but he estimates that there would have been over 100 and that the damage to each boat would almost certainly have been worse.

Like Swan Point, Indiantown Marina uses screw anchors that are drilled into the ground. Unlike Swan Point, Indiantown Marina houses predominantly sailboats, which have deeper keels so that boats ashore sit up higher and are more vulnerable in high winds. Scott Watson, Indiantown’s owner, said they use 4-foot helical anchors with round eyes, which are set into the ground using a posthole digger. He says it takes two men 10 - 15 minutes to install a helix. Boats are then secured with 10,000-lb. ratchet straps, which he says have very little stretch.

With anchors that screw into the ground, holding power is dependent on the density of the soil. Royce Randlett, who is president of Helix Moorings Inc., a company in Maine that sells helical anchors primarily for moorings, says any soil—no matter how loosely packed—offers at least some resistance and helps secure the boat. Randlett says they buried an anchor in loosely packed “sugar sand” in the Florida Keys and found that a 5 ½-foot screw anchor had 2,600 lbs. of resistance.

Watson says the anchors at Indiantown are secured into typical “Florida sandy soil” and notes that the longer the anchor has been embedded in the soil, the more holding power it seems to provide. The marina includes two straps per stored boat and will supply more for a fee—$30 per anchor and another $20 for the strap.

The marina was especially hard hit by Wilma and 33 of its 506 boats ashore were blown over when anchors were pulled out. Several other boats lost jack stands but, thanks to the straps, stayed upright. How many boats would have been blown over without the straps? Watson has no way of knowing for certain, but he estimates that there would have been over 100 and that the damage to each boat would almost certainly have been worse.

Helical Advantages: Easily installed and inexpensive. Has the potential to provide significant holding power.

Disadvantages: Holding power is dependent on the type of soil, which could get mushy in the heavy rainfall of a hurricane. Keel blocking can sink in mud, causing the boat to shift.

Sebastian River Marina

Eyes Embedded in Concrete Pavement — Sebastian River Marina, Sebastian, Florida

Just how well the straps work depends largely on how well they’re anchored. A short helical set in loose soil won’t hold as well as a longer helical buried in packed soil. At Sebastian River Marina, the straps used to secure the boats are secured to eyes set in concrete. Doug Hillman, Sebastian River’s owner, drilled holes into his concrete parking lot and tapped threaded sleeves into the holes. He then screwed eyebolts into the sleeves. As the bolts were tightened, the sleeves spread out at the bottom, which secured the bolts to the concrete.

Before storms, boats are strapped to the eyes with 5/8-inch, three-strand nylon line. The system works so well that none of the 56 boats, with an average size of 40’, stored ashore in Hurricanes Jeanne and Frances were blown over. It is worth noting that the wind was often on the beams of the boats and the parking lot was flooded with two feet of water.

Advantages of Concrete Pavement: Tremendous holding power.

Disadvantages: Expensive.


Chain and Eyes Embedded in Concrete Runners - Hinckley Company Marina in Stuart, Florida And Purerto del Rey Marina in Fajardo, Puerto Rico
Hinckley Company Marina

While anchoring boats to eyes embedded in concrete clearly has tremendous holding power, not many marinas have large (and expensive), concrete parking lots. A third alternative for anchoring boats ashore in storms is to use long concrete runners set into the dirt, sand, or gravel parking lot. At the Hinckley Company Marina in Stuart, Florida, the runners are about two feet wide and run the length of the parking lot. Using two-inch nylon straps, the boats are secured to lengths of ½-inch chain embedded in the concrete. The 2-inch nylon straps have a breaking strength of 30,000 pounds and are ratcheted tight to minimize movement. All of the 178 boats at Hinckley were stored ashore and most were held in place by the nylon straps secured to the concrete runners. (A few that were away from the runners couldn’t be strapped down.) Three of the boats that were strapped down were blown over in Hurricane Frances and two in Jeanne. According to Hinckley’s Gary Rolfe, the ground became so wet that the boats’ supports sank into the mud. All but one were repairable.

Puerto del Rey Marina

An almost identical system, with long concrete runners, is used in del Rey Marina in Puerto Rico. The only difference is that boats in Puerto del Rey are secured with 3/8-inch galvanized steel cables and turnbuckles. The system was installed after the marina was destroyed by Hurricane Georges and has yet to be tested by a major storm.

Advantages of Concrete Runner: Quicker to install and less expensive than concrete pavement. Tremendous holding power.

Disadvantages: Not many. Keel blocking can sink in mud, causing the boat to shift; this could be corrected with gravel or wider supports beneath the keel.


Gunwale to Gunwale?
Dave Hillman, the owner of Sebastian River Marina in Stuart, Florida, thinks another solution to the problem of boats toppling over in hurricanes would be to block them gunwale to gunwale in long rows, with blocks of foam between each boat. Boats that are only 8 to 15 feet wide individually would be 50 to 60 feet wide collectively. Even strapping one or two boats together would have a significant advantage over boats that are left to weather a storm individually.

In addition to strapping them to each other, Hillman would still recommend strapping them to the ground individually using earth anchors or eyes set in concrete. Two considerations: First, Hillman says the yard manager would need to have some feeling as to how the boats are going to go together; placing a boat with towering gunwales next to a boat with low freeboard wouldn’t work. Also, the yard would need to have a hydraulic trailer or forklift; a travel lift would not allow the boats to be placed close enough together. The technique would also allow the marina to store more boats in the same area. Hillman calls the idea of storing boats gunwale to gunwale with straps “bulletproof.”