For maximum maneuverability, the control lines-one port, one starboard-should attach at the widest part of the boat. This maximizes leverage and places the effort close to the center pivot point. On a catamaran, closer to the transom works because of the wide beam, but for monohulls, attaching near the pivot point at the keel will be more responsive. For maximum responsiveness, the drogue should be as close to the transom as practical-this results in more responsive steering and minimal drag. We found the best compromise to be around 65-80 percent of the way aft, where there is still enough beam, but less risk of the control lines fouling.
Before deploying, set the lengths of the control lines to about one-boat length; it is easier to start with the drogue a little too far back than to risk sudden turns and fouling the tow line. In moderate seas, you can grind the drogue in and set a course once the rigging is stable and stretched out.
When deploying in strong wind, the wind tried to hurl the drogues right back in our faces. Adding an eight foot tail of chain behind each drogue prevented this. Lower the chain first to avoid tangling. (Note: Galerider does not advise using chain).
As wind increases, ease the drogue back from the boat. This increases drag (steering force), and keeps the drogues stable. In strong winds, we set the drogue was about 60 feet behind the boat. For best control, reef earlier than usual. Keep the traveler lower than normal on all courses. As true wind nears the beam, consider striking the main.
Some sailors advise deploying the drogue from one side and attaching another control line from the opposite side, using a snatch block. We could not get this arrangement to work (see photo); instead we joined the lines with a camel hitch. Avoid shackles when joining lines. Use either splices or knots, which don’t introduce chafe, and make recovery easier or adjust. Make sure the safe working load of your tow rope and control line(s) match the drag load for your device at 7 knots. Also check the working load limit (WLL) of any winches used to retrieve the drogue. The drag should not exceed about 35 percent the working load limit (WLL) of the winches.
All of the drogues provided controllable steering on flat water and moderate waves. With the rudders stuck at about 60 percent to one side, and the drogues set off-center to counteract this, we could and steer a slow, steady course. In winds over 20 knots, only larger drogues could maintain courses to windward or with the wind near the beam. More drag is better in strong conditions, and in lighter conditions you can save fuel by pulling the drogue close and reducing chain weight to keep the drogue near the surface.
Steering under sail will vary greatly between boats. Some rudderless boats have sailed for days to windward without a drogue, using the engines prop walk and sail trim to counter any helm tendencies. Other boats (shallow draft multihulls in particular) will have trouble pointing once the wind picks up. In our tests, once sails and drogue were balanced and adjusted, course stability under sail was generally very good, although the boat yawed as much as 25 degrees in higher winds. In light winds, you may be able to set a spinnaker and still self-steer. Again, this may require experimentation.
Never underestimate the risk of getting a line under the boat. While it is possible to ease the work of hauling in the drogue by backing the boat under power, the risk of fouling the prop or rudder is great.