Cap'n Morgan wrote:
If your boat is in the water at a slip, there's plenty that you can do before the high winds hit. For starters, remove everything that can possibly catch the breeze. All canvas—biminis, isinglass and cockpit covers and their supporting frameworks—must come off. Additionally, wind-catching extensions like outriggers, moveable antennas and even anchors should be stowed aboard or ashore. Remember, a 60-mph breeze can tip a Volkswagen over and a 100-mph wind can carry it away, but not make the payments.
All lines should be doubled and made of nylon, not Dacron and never polypropylene. Lines should be of the largest diameter possible. But they shouldn't be so thick that you can't wrap one around the base of a cleat and form two figure eights. This is important because the lines will serve to "sling the boat in the slip. Fore and aft spring lines should be made up to the outlying pilings—the longer and at the most acute angle, the better. Therefore, springs from the bow and stern cleats should be made up to pilings as far forward and aft as possible; the same holds true in slips with bollards or cleats on the dock. Bow and stern lines should have enough slack in them to compensate for the greatest expected tidal change and be long enough to keep the boat from hitting the adjoining dock/pilings. It's the springs that will do most of the work. Ideally, you'll need to pull a line in to step off the boat and onto the dock when you're done. The spring action of the lines should pull the boat back and allow it to sit suspended in the middle of the slip (you'll still need fender boards). Naturally, wherever a line touches the boat, dock or another line, it must be chafe-protected—split garden hose, leather or even rags that are taped or sewn in place are ideal.
If you need to do all that, than at least you're boat should be on it's mooring. At best, out of the water and into land.
It goes without saying, on the mooring, your boat will alway be into the wind. Which will result in less damage. At the slip, your boat could be broad side to the wind. Putting even more stress on the cleats, risking both dock and boat slaming into each other. Plus, I am sure that they will call for all boats to leave there slips on a 60+ winds