[Valiente]

Guys, despite the large percentage of "conjecture" in this thread, it is good to debate the theory.

The reality, however, might be closer to this:

1) Tank tests are logically of only limited value in determining the applicability of drag devices. Nonetheless, that might be as good as it gets.

2) Real-life oceanic heavy weather, to all reports from those who've survived it, tends toward the chaotic. Few people are going to say "let's take my quarter-million buck yacht out into that whole gale to test the JSD, OK?" The whole point of these devices is that they are more or less worst-case options. It's therefore hard to gauge WHEN and HOW they are best deployed. By when I mean under conditions where it is safe to be mucking about with 120 little parachutes on deck without tearing off your windvane, hooking the backstay or fouling your prop or rudder. Like reefing, it's logical to assume a stern or bow drogue is best deployed some time before conditions merit it.

Whether people DO this is another story...particularly as mentioned, you generally try to avoid such conditions in the first place.

3) Knowing how to deploy these devices might be key to getting them to work properly. In that case, the stern chain plates might be the unacknowledged part of making the JSD work at its best (visuals be damned), just as a bow drogue needs some sort of bridle and block going aft and the proper scrap of sail plus rudder angle to "crab" effectively. They aren't quite "fire and forget" because you have to check for chafe, tangles, shackle deformation and generally be aware of the sea state. On top of that, with the JSD, you are still actively sailing. With hoving to under a sea anchor, you can, proximity to traffic and land permitting, leave the boat to its own (drag) devices.

I think the prudent seaman should have both aboard, and should practice in 25 knots until the bugs are worked out. Old-school sailors used chain, tires, and even anchors added to warps, plus the odd bag of fish oil. In respect that they lived to write how that worked out down, it's clear that anything that slows the boat below hull speed is of a positive benefit in high winds and breaking waves. There is no magic bullet, because there is no one boat and certainly no one sea state that is 100% predictable.

Some old salt in a wooden smack trailing a tire on 300 feet of hawsers in a storm who has done it a dozen times in 30 years is liable to have a higher survival chance than a guy in a Bavaria chucking a JSD off the swim platform for the first time. The merits of the JSD don't even enter into such an equation in this case if the guy with the Bavaria manages, due to a compromised deployment with such a powerfully loaded up drag device, to tear off his stern ladder leaving two fist-sized holes in his boat.

So if you own a drag device, go find 25 knots and eight foot seas and throw it out. Let us know how what works. That way, we'll have a better shot at avoiding tragicomedic results at 50 knots. Advocacy beyond that seems to me to be either theoretical or marketing-driven.