Correction. The Series Drogue has Flaws as a Steering and Speed Limiting Drogue.

I did a little testing of a shortened JSD and some other drogues over the weekend (8 years ago--publication was delayed due to agreement with Good Old Boat Magazine). It seems that the notion of a short JSD as a steering or speed limiting drogue is a failure. I have corrected that post.

It seems there are four fatal flaws:

1. The characteristic JSD "droop" does not occur at high speed. It is not a design characteristic, just a low speed characteristic. At higher speed (6 -7 knots) a JSD runs along the surface.
2. Cones are inefficient shapes. The Seabrake or Shark are about 50% more form efficient.
3. Cones are more unstable near the surface.
4. Small drogues are less stable near the surface.
5. The cones are too close together.

 The result of these factors is that a good drogue design (Galerider, Seabrake, Fiorentino Shark) is more stable and far easier to use than a series drogue for emergency steering and speed reduction.

A real survival storm? I still think that drogues in tandem, well-spaced, have a lot of merits, right up there with the JSD. For more discussion and data, read either "Faster Cruising for the Coastal Sailor" or an up-coming Practical Sailor article (though it will surely by hacked to size). A tandem drogue is easier to manage than a JSD, gives more options, provides the same drag (braking power), and runs just as deep.

 [Note. The secondary rode is NOT attached to the primary drogue, it is attached to the primary rode. It passes through the center. The drogues can be of other types--the illustration simply shows the pair I use. The Fiorentino Small Shark is excellent. The Delta Drogue is also good, although it is a bit less stable when near the surface.]