A JSD is unarguably the correct tool for most serious storm conditions. You can Google "JSD Coast Guard Report" for the details, so I will only summarize. IT was a truly clever leap forward that sidestepped many of the problems associated with conventional drogues:
- No single point of failure.
- Can't tangle.
- Can't be thrown forward by a wave.
- Can't pull out of a wave face, because the load is distributed.
- Very smooth drag.
- No single heavy piece to handle.
It has some short comings when used at higher speeds as a speed limiting drogue, or more importantly to me, for emergency steering:
- The cones will shred. Even the new improved ones may or may not be up to sustained 5-8 knot speeds, where the average load per cone is 2-10 times higher. Although reversal is not common, they will be working near the surface, breaking out of waves regularly and getting pounded. Being close to the surface is rough. Easy to test designs.
- Longer endurance may be required. It could be days, not overnight. On a long passage, it might be deploy several times, just for comfort.
- They are too close together for proper flow at the higher speeds. Testing of JSDs and plain cone drogues suggest drag is reduced about 30-40% by close spacing.
- No single large element to handle. Pulling a Delta drogue 72 over the transom in rough weather is no picnic. That is an understatement. Single drogues much larger than 2' (Seabrake 24, Delta Drogue 72) are simply not manageable by normal or aging sailor in boisterous conditions. Standard JSDs have a reputation for difficult recovery, but this would be 1/3 the length; I'm confident it is easier than a conventional drogue.
- Less chance of tangling during deployment or recovery. The worst time with a standard drogue is recovering it; I've had a few get in the rudders.
- Will not pull out of a wave. This is a considerable advantage, because EVERY conventional drogue becomes unstable above about 5 knots in the presences of steep waves. The wave increases the angle of the rode to the water and the drogue pulls out as the wave passes it. The best you can do is try to put this out of phase with the peak load, which in confused seas, is impossible. This is the primary reason conventional drogues can fail catastrophically as the storm rises; everything seems good, until the speed + load reach a critical level, the wave steepness builds, and the drogue pops out. If it is on a nylon rode, the rode contracts, the drogue snaps forward, and maybe the wind and breaking wave help it along. There is no magic design that can make a single drogue run deep enough to avoid this cycle. I observed this hundreds of times in testing.
- Drag will be more adjustable. Sometimes you need a lot of drag to make the boat track, and sometimes less would increase both speed and pointing (yes, you can sail upwind with a drogue, just not very high).
Recovering a Delta Drogue 72 (about 24-30 inches across). Even in clam weather it is heavy. Other drogues are awaiting their turn in the dinghy, including a Galerider, Paradrogue, Seabrake, cone, and JSD from Ace Sail Makers.
In use the drogue is often pulled in quite close to the transom, to reduce drag by lifting the drogue. This is how a Seabrake 24 deploys in 10-25 knots for emergency steering; in light winds it is in close, in stronger winds I you add an extension between the chain and the bridle.
So I wonder if a modified JSD (call it something different) might be the best possible answer:
- Fewer cones. Only about 1/3 the number specified for storm service.
- Strong construction. The current ACE Sailmaker method (they have up-graded the cloth and added a taped edge) may be acceptable, but 4 webbing straps would better support the cloth and would be more stable at increased speeds.
- Spacing should increase. This might also improve adustability, by making it easier to vary the number of cones in the water.
- Less weight. 10 feet of 5/16-inch chain should be enough, or an 8-pound mushroom anchor. The rogue will be more naturally resistant to surfacing at high load or high speed (same thing).
The most obvious difference is the that the series steering drogue is much longer, about 75-100 feet. But this is part of its strength--only by distributing the load can the drag remain steady is something as fragile and turbulent as water.
Cones can be purchased for about $7.00 each, although the upgrade cones might be $8.00. For a 35- to 40-foot boat this means about 30 x $8.00 = $240.00 plus the cost of 90 feet of rope ($90), or about $330.00. Assembled it would likely be about $400.00. A comparable conventional drogue is $299.00-$785.00, so no important difference in cost. The bulk and weight would be similar if Amsteel is used for the rope.
What do you think? I will be testing some designs, I'm sure, once I nail down my thoughts. I would love your input. I think there is potential here from something superior to anything on the market. A short, stout "Steering Series Drogue", designed to snake behind the boat at higher speed.