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[PSUBS-MAILIST] Boat Drogues



Hey Dean, 

Here is a link I though my might find interesting.

http://www.seaanchor.com/deltadrogue.htm

"Drogue or Sea Anchor?

The proper use of a Sea Anchor off the bow should not be confused with the proper use of a Drogue off the stern. The dichotomy between the two concepts along with documented case histories has been combined into a publication entitled the Drag Device Data Base (available from PARA-TECH). Sailors planning extensive offshore passages should obtain a copy with a view towards more in depth study of the different applications of both devices.
   
 

Speed Limiting Drogue

A speed-limiting Drogue is towed off the stern. It's purpose is to (a) limit the boat's speed, (b) reduce her angle of yaw and (c) to provide for steering assist in strong following seas. You can, and may have to, steer the boat with the Drogue in tow. There is a "Catch 22" with any speed limiting Drogue: The same low pull that allows for steering control may also allow the boat to broach, capsize and/or pitchpole in the heaviest seas. The forces that pitchpole yachts are formidable enough to yank the Drogue through the water in the course of throwing the boat end-over-end. Sailors should be aware of this "Catch 22" and make allowances for it in the course of their decisions at sea.
WARNING: In all likelihood the insufficient drag of a speed-limiting Drogue will not prevent pitchpole in the heaviest storms, especially those packing ESW's (Extreme Storm Waves), rogues and "Three Sisters" type developments.

   
 

Four Uses For Drogues

  1. The above notwithstanding, speed-limiting Drogues can be of immense value in strong following seas and have been used to stabilize craft since antiquity. No doubt there are many yachts sailing today that would have gone down had it not been for the grace of God and some sort of device that slowed the boat down.
  2. Towed off the stern with a bridle a speed-limiting Drogue can be used as an emergency steering device to yaw the boat if steering fails.
  3. Towed off the windward quarter a speed-limiting Drogue can help maintain directional stability while negotiating a dangerous harbor entrance.
  4. Towed off the stern of a vessel in tow a Drogue can all but eliminate the "whiplash" effect and contribute to better control by the towing vessel."

Your resident possibility thinker ;)'

Regards,

Szybowski