Parachute Sea Anchor

This morning's project was to become reacquainted with the deployment of my 18-ft diameter "Para Anchor" sea anchor. (See http://www.paraanchors.com.au/ for descriptions of deployment, retrieval, drift rates, etc. I've got the "Bass Strait 18".) As expected I learned that I wasn't quite ready for a fast deplyment in rough conditions because I had to resolve issues of the floats at the head of the parachute.

The first photo shows the core of the system. The red bag in the sunshine contains the parachute, with the canopy on the right and the parachute lines on the left. The system is designed so that you can place the entire bag in the water with the parachute deploying as soon as all of the slack of the line between the boat and the parachute has been taken up. With Pachuca's setup the parachute must be launched when hove to on a starboard tack (i.e. wind coming from the starboard).

To the parachute cords at the left of the red bag is one meter of chain designed to ensure that the parachute rides below the surface of the water during deployment.

The next photo shows the series of floats connected to the chain at the end of the parachute cords. There is a 15 m line of white rope (which floats, as it must do) tied to one of my large fenders. The purpose of this float is to prevent the parachute from dropping to directly below the boat if the wind dies down while the exhausted crew is asleep. Were this to happen there would be serious consequences: (1) the boat cannot lift out a trough of water because the parachute is holding it down, putting it in peril (2) pulling up the deployed parachute from 100 meters below the boat would be a daunting task. (I read of one crew that cut away the parachute rather than retrieve it from below.)

From this primary float is another white rope of 25 meters tied to the small red float. The role of this float is to facilitate retrieval of the parachute. I will explain this by describing what Arnold and I experienced when we retrieved the parachute after gale winds in Spencer Gulf, South Australia. Pachuca had hung well all night off the parachute, giving us a chance to get some rest and minimizing the loss of ground to 1-2 knots. We woke up in the morning to find gray clouds and winds down to maybe 15 knots. When we were ready we started the engine and headed for the parachute while Arnold steered the boat and I was on the bow shipping the 100 meters of 20mm (about 3/4 inch) nylon rope. We reached the red float that was being pushed down wind from the parachute. I shipped this float with the boat hook and pulled in the line which had the effect of pulling on the apex of the parachute canopy to the point where I was pulling the parachute by the canopy with most of the water drained from it (i.e. I "tripped" the parachute.) I then pulled the parachute on board, retrieved the rest of the line, and off we went.

The third and fourth photos show the connection of the "underside" end of the rope in the bag to the red deployment line. The red line is fixed to the toe rail with plastic ties. The other end is attached by a chain to the bow roller.

So the deployment sequence is as follows:
1. Heave to on starboard tack
2. Fetch one of Pachuca's large fenders
3. Place the parachute and rope bags on the starboard cockpit seat
4. Connect all of the lines, e.g. the floats and the main rope to the parachute canopy and red deployment line on the gunwale

At this point the boat is drifting more or less sideways to port.

5. Put out the trip line float and then the main float into the water and wait until the boat has drifted far enough to stretch their lines
6. Open up the parachute bag, drag a bit of it out of the bag, then lovingly place it in the water

After a time the boat would have drifted far enough to stretch the 100 of main line. This will cause the parachute to open and when it does it will feel like being on a real anchor. The force of the pull will break the plastic ties that hold the red line to the toe rail and before I know it Pachuca will be hanging from the parachute off the bow roller.

Then comes the best step:
7. Go down below, get into dry clothes, have a few stiff drinks, and go to bed.

Bob came by today. I told him that I had had no joy in telephoning Danny regarding the storm jib and he suggested that I tried hailing him on VHF 22 which he monitors whenever he can. I did this and got through to him. He does have something that may be suitable but he needs to measure it and asked me to call him on VHF 22 tomorrow after the end of the usual 8AM session.

No word from Colin. I told Bob that I'd wait until the end of the week at which time I would propose that he hand over the head to me and I'd have a go at installing it (after purchasing a torque wrench). Bob advised me that there is still time, it won't take Colin long to do the job once he's ready, and not to panic.