Originally Posted by hellosailor
"The only question now is why not just tow lines instead of a drag device."
I'd expect that the Jordan device creates more drag in less space, i.e. you can stow a Jordan device in a lot less space than the amount of lines you would need to tow for the same effect. Lines don't have much drag, compared to cones.
Yes and thatís my point. But different boats behave differently running side by side in the same storm. And different parts of the world have different wave shapes.
A catamaran or trimaran and a fast fin keel boat share something in common compared to my current boat, a Tartan 34C. They can sail under bare poles fast enough to lose control with enough wind. They also displace less then the same size full keel boat. I think you want to slow them down quite a bit and the Jordan Series Drogue is the safest way to do that while putting the least shock on the boats structure when you are talking about a light boat. Remember the strain on the drogue is a percentage of the boats weight so a light cat will have a smaller strain on the system then a full keel boat of the same length. With my all up displacement I might have a strain of 12,000 on the Jordan Series Drogue and thatís unacceptable to me.
Also I think in terms of staying square to the wave face while running and I want to slow the boat down but not as much as the Jordan Series Drogue would. If you slow down too much you will lose water flow over the rudder when the waves crest passes and at the wave top you have the greatest effect from the wind. I think itís a mistake to be in a part of the cycle with the greatest wind effect and the least available steering force. My plan is to keep enough boat speed to have positive steering at all points in the wave cycle. So I want less drag and more control. I also have a center board which will act like the feathers on an arrow when it is down just a little bit. The publications I looked at including the paper written by Jordan all seem to agree that being rolled while running is connected to losing control and broaching. The speed doesnít scare me as much as the broach does. You can avoid a broach by having enough drag to keep the stern to the seas or slow the boat and steer. I have confidence in my windvane and because a random wave will have the same effect on the boat using either system I will use lines as a drag.
My thinking also includes the fact that seas breaking aboard in the cockpit and cabin area are not a good idea. I think, and this is just an opinion that adding 12,000 pounds to the stern will hold the stern and makes it a target for the seas instead of having just 5,000 pounds which will more easily let the stern rise to the waves. I have had seas sweep the boat and itís not any fun. I want to avoid that in the future.
I sail in the North Atlantic now and if I wanted to travel in the southern oceans I would approach this differently. Pitch poling is a greater risk there because the fetch permits a larger and steeper wave. I also see a connection between boat sizes and being pitch poled. If I wanted to sail under those condition I would select a larger boat then I have now and because the line pull from Jordan Series Drogue as a percentage of displacement decreases as boats get larger I would consider adding one then. The lose of boat control at the wave crest is also a problem that becomes less as the boat gets larger because of the increased inertia a larger boat has. She will keep moving unless she hits something solid.
Lots of variables and permutations make for lot of solutions available to the skipper. Whatever plan you select you need to keep in mind that changing plans after things get really bad is usually a very bad idea. And one limiting factor is that if you didnít bring it you donít have it. So if you think you might want to try a Jordan Series Drogue donít forget to pack one. I already carry lots of heavy line so I am prepared to implement my plan, and my backup plan, and then my fall back plan. And if all else fails I can switch to my ultimate plan.
All the best,