How To Prepare For Wind
By definition, hurricanes and tropical storms have winds of at least 39 mph (which is when storms get a name) while hurricanes start at 74 mph and have been recorded at more than 150 mph. What's not always understood is that as the speed of the wind doubles, its force quadruples. In other words, the damage wind does increases much faster than its speed. This illustrates the importance of reducing your boat's windage — the area your boat presents to the wind — by removing as much rigging, canvas, and deck gear as possible. Whether your boat is stored ashore or stays in its slip, the less stuff the wind is able to push around, the safer your boat will be. Biminis are sure to get shredded in a strong storm, so take off the fabric and the frames. Strip off outriggers, antennas, running rigging, booms, life rings, and dinghies. Remove cowling ventilators and seal the openings. Furled headsails have a surprising amount of windage and are one of the first things damaged by wind, so they must be taken down. Not only can they shake your rig apart when they unfurl (and no matter how well you secure them, in a big storm they probably will), they can cause damage to your neighbor's boat as well. Mainsails are bulky and should be removed also.
How To Prepare For Rain
Rainfall of six to 12 inches in 24 hours is common during a hurricane, and as much as two feet can fall in a day. Cockpit scuppers can be overwhelmed by such torrents, and even boats stored ashore can suffer damage if rainwater overflows into the cabin. Boats stored in the water can be sunk when rainwater backs up in the cockpit and the weight forces deck drains underwater, causing them to backflow.
Make certain cockpit drains are free-running. If your boat is staying in the water, remove heavy items from the stern area, such as anchors, extra fuel tanks, and kicker motors, so that the cockpit scuppers are higher above the water. Close all but cockpit drain seacocks and plug the engine's exhaust port. Use masking or duct tape to seal around hatches, ports, and lockers to keep water from getting below. Seal exposed electronics. Make sure the bilge pump and switch work, and that the battery is topped up; shore power is not likely to remain on throughout the storm. Keep in mind that the ability of the pump and battery to remove water is usually greatly overestimated. Small boats should be covered if possible.
How To Prepare For Waves
Hurricanes and Tropical storms build up surprisingly large waves quickly, even in relatively small harbors, bays, and lakes. The longer the distance over which the wind can build up waves, the bigger the waves. Waves make boats bounce in their slips, displacing fenders and increasing strain on docklines.
Exposure to waves can pound a boat against the dock. Small boats should be trailered inland.
Double up on docklines and make sure all are well-protected from chafe. While fenders and fender boards won't compensate for poor docking arrangements, if the boat is well-secured, they may offer some additional protection, especially if they are heavy duty. Smaller boats can be overwhelmed, especially if they are stern-to to the waves. The bow is strongest and least likely to be overcome by water and