BOAT wrote:Looks like a full on planing hull - I'm still a bit confused on that - it's one thing to blast around the bay but what happens in the heavy seas? That's really what my whole premise was about.
In the big ocean with storms that are inevitable what happens?? It still seems to me that the narrow boat will be a LOT more comfortable, (and safer too).
I thought you guys said racing did not matter?
So again, the whole point of WIDE is for interior room again??
Beam has two uses: Interior room of course, but it also provides a "catamaran-like" form stability to monohulls. Form stability refers to the ability of the hull to remain stable without the use of ballast, the way cats and tris do. But just like cats and tris, form stability upright means form stability when upside down as well, meaning it reduces roll speed and could possibly remain inverted. A wide beam is also more subject to capsize when struck beam-on by a breaking wave, however, it's not that much less stable and its actually not entirely clear whether its an overall disadvantage.
The 1979 FastNet disaster and the Hobart disasters provided a lot of information about storm tactics and boat stability. ISO has developed the "stability index" or STIX based on that data with insurance companies to create a single rating that classifies a boat's susceptibility to capsize and it's roll period. They use this data to rate boat's survivability in heavy seas, and this boat >just barely< rates "all ocean" for eight people. It's amongst the least expensive boats that rate "All Ocean", and frankly I can't really afford more at this time in my life.
Nothing beats length for survivability. The bottom line is the longer your boat is, the bigger a wave it can survive. So your best tactic is to get the longest boat you can afford (which is what I did).
It's important to understand that no sailboat is immune to capsize. No monohull should capsize in sinusoidal waves of any height, but breaking waves are always dangerous. In breaking waves, both narrow and beamy boats can survive a 55% LOA breaking wave if faced bow-on. Beyond that, they will all pitchpole.
The difference in form stability comes when hit beam on: A narrow boat can survive a wave up to 44% of LOA while a beamy boat can only survive up to 33% of LOA. Its important to understand that these differences are relatively unimportant: The difference between those two numbers is small, and if you've been hit by a 33% LOA wave, you're going to eventually be hit by an even bigger one in the same storm.
Where narrow boats have a real advantage is the time they take to roll: They're much faster to return to upright than a beamy boat.
Because no boat can avoid capsize entirely, the next tactic to go for is to avoid turtling, and to return to upright before crew harnessed in the cockpit would drown. The higher a boat's angle of vanishing stability is, the faster it will return to upright in a capsize. Beamy boats are slower to return, narrower boats much faster. The "All-Ocean" rating requires that a boat return to upright after capsize within two minutes. Because no catamaran or Trimaran will actually return to vertical after capsize, many people do not consider them to be all-ocean capable.
The race disasters showed one thing clearly: Storm tactics by the crew trump form stability for resistance to capsize. None--not one--of the boats that properly hove-to and stopped racing in both storms were capsized. By keeping bow to the wind and waves, any boat will survive a storm that is survivable based on its length. Some beamy boats that lied a-hull did turn turtle, but the vast majority of casualties occurred on boats that attempted to run after being hit by the storm, continued to race, or otherwise attempted to make headway.
Storm tactics are pretty simple:
1) Keep an eye out for breaking waves. They are the real danger.
2) Should breaking waves occur, immediately stop attempting to make headway, execute a hove-to, and (if possible) engage an autopilot to assist in keeping the hove-to. I think the jib should be lowered or furled completely to move the CE as far aft as possible. The best thing to do IMHO would be to hoist a separate hank-on off the backstay similar to an anchor sail whose purpose is to keep the boat pointed directly at the wind and prevent the main and jib from being damaged. This small sail is also going to cause less drag in the water if the boat capsizes, which will make its return to upright faster. If you have split back-stay, a hank-on that acted as a drag-chute would be ideal.
3) Deploy a storm drogue. Anything you can do to keep the boat pointed naturally at the breaking waves should be done.
4) Go below and baton down. Surviving a capsize means making the cabin as watertight as possible, so stuff any cracks (such as the companionway hatch) with a large towel that will slow prevent water ingress, but you can pull out in an emergency if you have to escape. Do not try to keep the helm in breaking waves. Fix the rudders straight to reduce the possibility of them pulling the boat off course or breaking, or pull them up if possible. The daggerboard or fin keel should remain down.
4) Harness yourself to prevent injury, but keep a knife on your person to cut away the harness if necessary.
5) Wait for the storm to blow over.
If you're inside the cabin of a reasonably tight boat that is all-ocean rated, the difference between beamy and narrow isn't going to matter much because you won't be in the cockpit drowning while you wait for the boat to return to upright. As long as the boat will eventually roll back onto its hull, you will survive. The fool's errand, in my opinion, is in attempting to keep the helm in a storm.
Now as to comfort, well, I don't know. I'll just have to find out. Certainly not as comfortable as a MacGregor 70 in heavy seas
