The Jordan Series Drogue

Storm Tactics · Offshore Safety

The Jordan Series Drogue occupies a specific and important position in the spectrum of storm tactics: it is the device designed for the condition where everything else has stopped working. When seas are breaking heavily and a boat hove-to is at risk of capsize from a broadside crest, when running off under bare poles is generating too much speed on steep wave faces, when lying ahull would present the beam to the worst breaking water — the JSD is the device that was designed to answer those conditions and that the research shows actually does so.

Don Jordan, a retired aeronautical engineer, developed the series drogue following the 1979 Fastnet Race disaster and subsequent analysis of yacht capsize dynamics. His research, funded by the United States Coast Guard, identified the fundamental problem: conventional drogues and sea anchors had single points of failure, inconsistent drag characteristics in steep breaking seas, and shock loading that could damage the boat or the device. Jordan's solution was elegantly different — distribute the drag across many small elements, eliminate the surge-and-snatch cycle, and make the system robust enough that no single failure could compromise it.

How It Works

The Jordan Series Drogue consists of approximately 100 small fabric cones — each roughly two inches in diameter — attached to a length of 5/8-inch three-strand or braided line at regular intervals. The total length of the device is approximately 300 feet, with a heavy weight at the bitter end to keep the device extended below the surface and prevent it from collapsing in a breaking sea.

The progressive drag from 100 cones spread over 300 feet has a fundamentally different characteristic from a single large drogue. A conventional drogue generates most of its drag from one device that can surge backward as a wave crest overtakes the boat and then snatch forward as the wave passes, creating shock loads that can be enormous — enough to carry away cleats, rip through decks, or part the drogue line itself. The series drogue generates relatively constant drag because at any given moment, some cones are in the wave face (generating high drag) and others are in the trough (generating less), and the total load averages out across the system. There is no single snatch point.

The controlled speed result — 2 to 4 knots running before the sea — keeps the boat moving forward just enough to maintain steerageway and stern-to orientation while preventing the dangerous acceleration down a wave face that leads to broaching or pitchpoling. The stern-to orientation is the critical point: it keeps the narrowest, strongest part of the boat pointed into the most dangerous water.

Why It Works When Other Devices Fail

Jordan's capsize research established something that was not well understood before his work: offshore sailboats capsize most commonly not from sustained heeling in high winds but from being caught broadside to a breaking wave crest. A breaking wave — not a steep but non-breaking wave, but an actively breaking crest with a collapsing face of aerated water — can apply a nearly instantaneous lateral force that exceeds the righting moment of even a well-ballasted cruising boat. When that wave hits a boat lying broadside, capsize is the predictable result.

The JSD prevents this by keeping the stern to the sea consistently. With 300 feet of drogue between the boat and the wave, the boat has time and resistance to maintain its orientation even as wave crests overtake it. The bridle arrangement — two stern attachment points rather than a single centerline attachment — adds directional stability. A boat with a JSD deployed cannot easily swing broadside because the drag resists any such movement immediately.

This is the critical difference from heaving-to in breaking sea conditions. A hove-to boat sits at 50 to 60 degrees to the sea — which means a breaking crest hitting the boat at that angle has significant broadside leverage. In moderate breaking conditions, the hove-to slick reduces this risk. In severe breaking conditions, it does not eliminate it. The JSD changes the boat's orientation entirely: stern to the breaking water, the hull's most robust and hydrodynamically stable aspect to the worst of the sea.

The Difference from a Parachute Sea Anchor

Both the JSD and a parachute sea anchor are storm survival devices, but they work on opposite principles and produce opposite boat orientations. This is a source of genuine confusion among sailors who have not used either.

A parachute sea anchor deploys from the bow on a long rode and holds the boat bow-to-sea. The boat faces into the wind and waves, makes almost no headway (drift is 0.5 to 1 knot at most), and is in effect anchored to the water rather than the bottom. The Pardeys and other experienced cruisers have advocated strongly for the parachute sea anchor, and it works well on appropriate boat types in appropriate conditions.

The JSD deploys from the stern and allows the boat to make 2 to 4 knots of headway downwind while keeping the stern to the sea. It requires sea room downwind — you will cover 30 to 50 miles before conditions ease — but it keeps the boat in a moving, manageable state rather than stopped in the wave face.

The contemporary offshore research consensus, informed by Jordan's work and subsequent experience, tends to favor the JSD for breaking sea survival conditions over the parachute sea anchor, primarily because a bow-to orientation in extreme breaking seas can expose the bow structure and on-deck crew to direct wave impact. The decision between them depends on boat type, crew experience, and available sea room. The full discussion is in the companion article on parachute sea anchors.

Building or Buying

Jordan's original design specifications are publicly available — he chose not to patent the device, and the complete construction details have been published widely. Building a JSD from materials is entirely feasible for a competent sailor who is comfortable with a sewing machine and can work with line. Materials cost $200 to 400 depending on the quality of line and cone material chosen. The construction requires careful attention to the cone spacing and attachment — the design is not complicated, but precision matters — and the resulting device performs comparably to commercial versions.

Commercial JSD manufacturers include Ace Sailmakers and Hamilton Ferris, among others, who sell complete, tested devices in the $500 to 900 range depending on size and specification. A commercially made JSD has the advantage of professional construction and known materials, which some sailors prefer for a device they are trusting with their lives.

Whichever option you choose, the bridle is as important as the drogue itself. The bridle consists of two heavy lines — typically 5/8" or 3/4" nylon, which stretches to absorb shock loading — each running from a substantial stern cleat or mooring bitt to a central connection point where the JSD line attaches. The loads on the bridle in survival conditions are very large; the attachment points must be through-bolted to substantial structure, not simply screwed to the deck. If your boat's stern cleats are the type used for occasional dock lines, they need to be upgraded before the JSD is a reliable option.

Deployment Procedure

The JSD is most effectively deployed from a bag or bucket at the stern, with the cones flaked carefully so they run out without tangling. The weight at the bitter end goes over first, followed by the cone-studded line, deployed by hand into the wave face as the boat runs before the sea. The line pays out as the boat's forward motion takes it, with the crew feeding it over the stern or quarter without tangling it in the propeller — which means the engine should be in neutral during deployment or the prop should be stopped.

As the drogue deploys and begins to drag, the boat decelerates noticeably. Allow the full length to pay out before securing the bridle connection. Once the full drogue is out and the bridle is cleated, the boat should settle into its running attitude at 2 to 4 knots. Monitor the bridle for chafe — where it passes over the transom or through a chock is the most likely wear point. Chafe protection should be rigged before conditions make this difficult to address.

The decision to deploy should be made before conditions are at their worst, not after. Deploying a JSD from the deck of a boat that is already being overwhelmed by breaking seas is significantly more dangerous than deploying it while conditions are serious but manageable. If your forecast or sea state suggests the JSD may be needed, rig the bridle and stage the deployment bag before the decision becomes urgent.

Recovery: The Hardest Part

Recovering a JSD after the storm passes is the operation that most JSD owners underestimate. The drogue is 300 feet of cone-studded line that has been in the water under load and now needs to come back aboard. On most cruising boats, there is no powered winch rated for the recovery load, and hand recovery in post-storm conditions — even if the wind has dropped — requires sustained effort over an extended period.

The standard recovery technique involves leading the JSD line to the primary winch and grinding it in, using the snubber as a pause point to allow recovery in stages. A block-and-tackle recovery pennant — a separate line rigged specifically for recovery — can be pre-attached to the drogue's bitter end before deployment, giving you a mechanical advantage for the initial recovery phase when the load is highest. Once the weight at the end of the drogue is aboard and you are recovering the cone section, the load reduces, but 300 feet of wet 5/8" line is still substantial.

Budget two hours for recovery in post-storm conditions with two crew working. Flake the recovered drogue carefully as it comes aboard to prevent tangles on next deployment. Inspect the cones and line for wear and damage before restowing. The drogue should be ready for next use before you are back in port.

Frequently Asked Questions

Who developed the Jordan Series Drogue and what was the research basis? Don Jordan, a retired aeronautical engineer, developed the series drogue following the 1979 Fastnet Race disaster and subsequent analysis of yacht capsize dynamics. His research was funded by the United States Coast Guard and identified the fundamental problem with conventional drogues: single points of failure, inconsistent drag characteristics in steep breaking seas, and shock loading that could damage the boat or the device. Jordan's solution distributed drag across many small elements to eliminate the surge-and-snatch cycle. He chose not to patent the design, and the complete construction details have been published widely.

What is the physical configuration of a Jordan Series Drogue? The JSD consists of approximately 100 small fabric cones — each roughly two inches in diameter — attached to a length of 5/8-inch braided line at regular intervals. The total length is approximately 300 feet, with a heavy weight at the bitter end to keep the device extended below the surface and prevent it from collapsing in a breaking sea. It deploys from the stern via a bridle attached to two substantial stern cleats or mooring bitts. The device controls boat speed to 2 to 4 knots running before the sea, maintaining steerage while preventing dangerous acceleration down wave faces.

Why does the JSD prevent capsize when conventional drogues cannot? A conventional drogue generates most of its drag from one device that can surge backward as a wave crest overtakes the boat and then snatch forward as the wave passes, creating shock loads enormous enough to carry away cleats or part the drogue line. The series drogue generates relatively constant drag because at any moment some cones are in the wave face generating high drag and others are in the trough generating less — the total load averages across the system with no single snatch point. Jordan's capsize research established that offshore boats most commonly capsize when caught broadside to a breaking wave crest, and the JSD prevents this by keeping the stern consistently to the sea.

How does the Jordan Series Drogue differ from a parachute sea anchor? The parachute sea anchor deploys from the bow on a long rode and holds the boat bow-to-sea, making almost no headway — effectively anchored to the water. The JSD deploys from the stern and allows 2 to 4 knots of headway downwind while keeping the stern to the breaking water. The contemporary offshore research consensus, informed by Jordan's work, tends to favor the JSD for extreme breaking sea survival conditions because a bow-to orientation exposes the bow structure and on-deck crew to direct wave impact. The JSD requires sea room downwind — approximately 30 to 50 miles before conditions ease — which the parachute sea anchor does not.

What does the JSD cost and what bridle attachment requirements must be met? Building from Jordan's publicly available plans costs $200 to $400 in materials. Commercial manufacturers including Ace Sailmakers and Hamilton Ferris sell complete tested devices for $500 to $900 depending on size and specification. The bridle — two heavy nylon lines typically 5/8 to 3/4 inch, which stretches to absorb shock loading — must be attached to stern cleats or mooring bitts that are through-bolted to substantial structure. Standard dock cleats screwed to the deck are inadequate for the loads in survival conditions and must be upgraded before the JSD is a reliable option.

When should the JSD be deployed and why is timing before peak conditions critical? The deployment decision should be made before conditions are at their worst — deploying a JSD from the deck of a boat already being overwhelmed by breaking seas is significantly more dangerous than deploying while conditions are serious but still manageable. Rig the bridle and stage the deployment bag before the decision becomes urgent. During deployment, the engine should be in neutral or the propeller stopped to prevent the cone-studded line from fouling the prop. Recovery after the storm takes approximately two hours with two crew working and should be planned for rather than improvised.