Are you aware of such an instance of damage to the stern of a catamaran deploying a Jordan Series Drogue?
I am not saying that the concern is illegitimate, but the drogue acts to minimize the forces acting on the boat while a sea anchor tends to present shock loads. Do you agree with that part?
I remember some test video on the Jordan site or linked to by it, but I am not finding it. It shows the effect of a large breaking wave on the boat. The idea is to maintain some forward motion, but not allow the boat to surf down the wave and crash out of control. Instead, the boat continues forward with the drogue providing a retarding force increasing with the square of the speed of the boat. That allows the boat to be lifted up under the wave with the breaking wave impacting the boat as gently as possible, under the circumstances.
I believe quite the opposite occurs, actually, and it was expressed by Steve Dashew in my original cite. One of the problems with the JSD it that it can exert a powerful DOWNWARD
pull on the stern - which is only increased as the attitude of the boat changes as it begins to surf down the face of a wave, and the 'bungee' effect of the drogue only increases as the crest of the wave approaches the boat...
Anyone deploying a series drogue in storm conditions had better be prepared for being pooped routinely, and have a bulletproof companionway and a cockpit that drains quickly... Many cats are extremely vulnerable to a breaking sea from astern, hence my own reluctance to consider lying to a drogue in heavy weather in a typical cruising cat... Well, aside from the fact that I will likely never find myself offshore aboard one, to begin with... :-)
Here is another question. Are you aware of an unsuccessful deployment of a jordan series drogue on a catamaran? If so, I would like to read it. I remember reading that the concern about presenting the stern is common, but it never really ends up being an issue in practice.
Again, such accounts are few and far between, I'm not sure the absence of any disaster stories re multihulls streaming a drogue is proof that it will necessarily be a successful tactic...
As far as the swinging doors, what if they fit recessed into the sides of the companionway such that they did not catch or snag on passers by? I like the idea of being able to seal it up quickly. And, crew can quickly come and go minimizing the time that it is open.
Creating such recesses would be a more expensive way to build a companionway, of course, and I've yet to see it on any boat I've run... Last boat that had them was a Cabo Rico 42, but at least they were set on take-apart hinges so that the doors could be removed, and stowed elsewhere...
Drop-down 'window shade' style drop boards are a pretty slick way to go, and are becoming more common, particularly on Euro boats... But they can also have 'issues', I once had the boards on a Trintella 50 get stuck in the recess below the sill, and it required a bit of taking apart of some finely finished cabinetry below to get them out... KISS, conventional drop boards with a convenient and secure rack for stowing them is still the best way to go on most boats, in my opinion...
I was speaking to a Jeanneau engineer at a boat show about the windows. I will see if I can get some data on their strength. Again, it is a valid concern, but let's see what the engineering data says.
Well, this wasn't a Jeanneau... But, I'll rely upon what I saw with my own eyes, and heard with my own ears this day, rather than waiting for what the "engineering data" says about the seaworthiness of putting picture windows in the hulls to today's production boats built primarily to a price point... :-)