Staying aboard is a terrible idea! says Bob Adriance, the Technical Director at Boat US, which insures some 200,000 boats in the U.S. There is little if anything you can do to protect your boat and its extremely dangerous. People have been killed.
Adriance advises that location is the biggest factor in determining how safe your boat will be during a hurricane. A small seawall wont do much to protect your boat from the surge and the breaking waves, but if youre in a well-sheltered harbor, your boat has a much better chance of surviving. The type of dock is also important. Plenty of boats survive hurricanes on fixed docks, but the mortality rate is typically much lower at floating docks with tall pilings. The latter allows boats to ride and fall with the surge without straining dock lines.
According to Adriance, the safest place to keep a boat in a hurricane is ashore on high ground. A key consideration is the boats mast, which presents a lot of windage. Getting your rig unstepped greatly reduces a boats windage, but its often difficult to do this before a hurricane arrives. A more practical alternative, used by increasingly more marinas, is to steady boats by strapping them to anchors in the ground, says Adriance. Depending on how its done, strapping can significantly reduce damage.
If youre going to leave your sailboat in the water, Adriance says its essential to reduce windage by removing biminis, dodger, and sails, especially headsails, which are almost guaranteed to come unfurled. Also, if youre in a marina, see if you can relocate to a bigger slip and secure long nylon lines to pilings that are further away.
If you keep your boat on a mooring, Adriance advises that the most important question is Whats below the water? He says tests have shown that concrete blocks are the worst mooring anchors as they lose 50 percent of their dry weight when submerged; mushrooms are next worst, followed by Dor Mor anchors (a mushroom variation). Adriance says mooring helixes (which are screwed into the bottom) are almost certain to stay put in a hurricane.
Next, you must consider chafe. On a breezy summer afternoon, a chains weight acts as a shock absorber, but in a hurricane the chain will be drum tight and nylon pennants must absorb all of the energy. Chafe, both internal and external, accounts for about half of all mooring failures in hurricanes. Adriance offers three suggestions: Use only new line, which retains all of its breaking strength. Use polyester chafe protectors, which will wick water and cool heated nylon fibers. Or, as an alternative, use polyester which is stronger and more chafe resistant through the chock, spliced to a nylon line to absorb energy down to the mooring ball. You need two pennants minimum, but some boats have used as many as five in a storm. Finally, you should also have been inspecting your chain regularly, and replacing it when it begins to show significant wear.
If your marina or mooring field isnt protected and hauling the boat out isnt an option, its time to go to a hurricane hole. You should take the time to scope out a good, well-protected spot well before hurricane season. Adriance advises that canals are excellent. One technique that has had great success is using a combination of anchors and lines to trees ashore, says Adriance. The more anchors and lines, the better.
Lastly, Adriance recommends removing valuables, including the vessels documents, closing all but the cockpit drain seacocks, maybe draining your water tanks, and shoving a plug into the engines exhaust port. The latter will help prevent water from reaching the cylinders just dont forget to uncork it before starting the engine.
For more information, check out www.boatus.com/hurricanes