Practical Sailor has covered storm preparation on several occasions. The two most extensive articles appeared in July 2008 Gear for Battening Down Ahead of Storms, and Tropical Storms Dos and Donts, from November 2011. We also have an online article How to Help Your Boat Survive a Major Storm. What follows are just a few tips relevant to securing your boat in a marina when you have exhausted all other safer alternatives.
If you do not yet have mid-ships cleats, add them. These should be sized and backed in the same manner as bow cleats, since loads are the same or greater.
Dock line size varies both with boat size and expected wind speed. Boats docked in hurricane or other severe weather areas should consider going up a size from common recommendations. However, your deck cleats may not accommodate what is really required. New cleats and backing plates may be in order.
Loads on the cleat of a 35- to 40-foot boat during an actually hurricane can exceed one ton. While boatbuilding standards (the American Boat and Yacht Council in the U.S.) specify load carrying ability, some older dock cleats are not up to snuff. Do you trust the dock cleats and pilings at the anticipated loads (1-2 tons for 35- to 40-foot boats)? If not, find alternate anchor points.
Remember the chafing gear. Preferably something water can permeate for cooling and lubrication. For a round-up of effective chafe gear see Round 2: Chafe Gear for Mooring and Dock Lines, October 2012.
Removing canvas and sails reduces windage. Specifically, remove the furling jib, one of the most common storm casualties. Dodgers and other canvas will also suffer if left up during the storm.
Dont leave anything on deck. Even dense objects can be blown across the deck and do damage, or be lost overboard.
Check your neighbors lines. If the boat appears to pose a threat to your own, try to contact the owner, and notify the marina staff if that is not possible. Failing these, deciding whether to take action yourself is a personal decision. What would you want someone to do if the boat was yours?
Any marina facing significant storm surge is not safe, but those protected from a long fetch by a low wave barrier are particularly vulnerable. Boat owners on the Chesapeake got an expensive lesson in this during Hurricane Isabel.