Sea Anchor/Drogue for Heavy Weather??

[Tiny Tim]

ModEdit: Sea Anchor/Drogue discussion vector, Split from Beaufort Limits thread ~fc

. . . being out in 70+ knots in a Mac is another story! More details please.

Eric, You joined this group too late to see the thread that (partially) described his 10 years on Zeno's Arrow. Since Mike Dunn is an infrequent visitor it could be some weeks before your answer arrives. You may want to grab some background reading in that linked thread.

Mad Mike's adventures on his Mac are certainly remarkable and his skill is probably more a testimony than the boat itself. Most of us, however, would not take on an ocean crossing in a Mac. . . .

A few points on heavy air sailing on a Mac. In my case, since I face heavy winds with such frequency, I decided to make a number of mods to deal with the conditions. First, I want to say that the rig must be tuned to get rid of as much mast rake as possible. I had my original forestay turnbuckle cranked all the way down. This helped a lot. I recently replaced the forestay with thicker wire 5/32" and had the stay cut 2" shorter than stock. This helped even more. If you don't seriously reduce mast rake on a Mac you will be constantly rounding up into the wind in anything 20kts+ . . .

I have heard it said many times by Mac X and M owners that when the sailing gets tough, they are delighted to be able to rely on big horsepower to get home. I have a Mac classic and that is not an option for me.

When the waves get high, the outboard, (a long shaft version) comes out of the water half of the time and is effectively useless. Others with a 10 hp and less on the transom will relate. I find myself wondering whether the prop of the big motors can be relied upon in steep waves driven by heavy winds. Do they not come out of the water?

Last month I was caught not once but twice by Force 8 winds on Lake Ontario. Thankfully the fetch did not allow full wave heights to develop. In one case, I was ten miles out and faced 3-3.5 meter waves (9.9-11.5 feet) and in the other case only a mile offshore and the waves were no more than 1.5 meters. These conditions were no problem for the boat.

In the large wave situation, I deployed a parachute sea anchor which worked very well in the storm. I had one seasick crew member. The side to side motion and centerboard banging was very uncomfortable (15-20 degree heel with a fast motion). That amount of oscillation is potentially dangerous down below if you are trying to move around.

I lifted the rudder, and that helped. I lifted the centerboard but the oscillation side to side seemed faster; so I put it back down and suffered the banging.

The same day I got back, I bought 8 Davis Rocker Stoppers for next time.
I am hoping they will slow the side to side oscillations and maybe reduce the overall heel in an anchorage/sea anchor situation. I have not had a chance to try those yet.

If you carry a sea anchor, the Mac will handle Force 8 in limited fetch conditions and in truth, I think it could have taken much more. BTW, I nearly ripped out the factory deck cleat with the sea anchor. I then used the bow eye (where the trailer winch hooks on) and that worked well.

I have a 5 ft. diameter parachute sea anchor and I have no idea whether a bigger one would work better. It did what I wanted it to. It pulled the bow toward the waves. The waves struck the port forward quarter so the boat was riding in a close-hauled angle to the weather. On analysis of my situation later, I concluded that I might have been able to point the bow closer to the wave direction if the tiller had been lashed to leeward.

I had been trying to sail to weather prior to deploying the sea anchor but I could not make headway. I could have dropped sail and bare poled but the the worsening forecast indicated that the worst of the conditions had not yet appeared and I did not want to be exposed to a greater fetch and therefore larger waves.

We did continue to lose way with the sea anchor but at the rate of .8-1 knot(s) per hour instead of 6+. After a three (plus) hour wait, we had steady 20 knot winds for a perfect 25 mile beam reach home.

That was the first time I had deployed a sea anchor. Sure glad I had it!

[Frank C]

Great report, Tim. Sounds as if you have a 26S??

Did anyone else read about the series drogue? I found the link within this other CruiserLog link by Jots. The stories I read about that series drogue were amazing, but I forgot to save the bookmark.
There also was an embedded link to the USCG testing of the device.

EditoADD: Never mind ... found it.
If you want the quickest, thumbnail sketch of what a series drogue is, read this one page.
The amazing stories I read are listed within the Jordan Series Drogue website.

I developed this drogue in conjunction with the Coast Guard. It is the first and only such device to be specifically designed for a 'worst case' breaking wave strike. Such a strike is described in Miles Smeeton's book 'Once Is Enough'. Modern engineering tools such as scale model testing in flow channels and breaking wave tanks, computer dynamic simulation, and laboratory testing for structural strength and durability were used in the development, as well as full scale testing using a 42-foot Coast Guard powerboat. The final design was tested in large breaking waves at the Coast Guard National Motor Lifeboat School in Ilwaco, Washington. This work is described in U.S. Coast Guard Report C.G.-D-20- 87, Investigation of the Use of Drogues to Improve the Safety of Sailing Yachts., U. S Dept. of Commerce Nat. Info. Service, Springfield, VA 22191 ($22).

The series drogue has now been at sea for over 12 years. At least 500 - and possibly over 1,000 - are in use all over the world. Many skippers have made their own, a tedious but not difficult job. The drogue has been deployed in many storms, including at least two of hurricane strength. The record has been flawless. No boat has suffered any damage, no crewman has been injured, and the drogue has been retrieved in the as launched condition. Every skipper has been satisfied with the performance. This conclusively puts to rest the old fear of being pooped when held stem to the waves. There are simple and sound engineering reasons for this most remarkable performance.

Counterpoint:
On Larry & Lin Pardey's Cruiser Tips website, they write that a para-anchor is better than a series drogue. But reading the testimonials on the Jordan website, a series drogue is what I'd want to deploy in a serious storm.

[Frank C]

Again, compelling testimonials (methinks) from the Jordan website:

Contest 40, 250 mi. N. W. of Bermuda. " Gusts were furious now. The seas were 25 ft with faces at 45 degrees and breaking crests. Deployed drogue. Slowing effect was phenomenal. Deploying the drogue was like jumping off a 30 ft. wave with a 40 ft. yacht. The feeling of being elastically tied to the sea itself is hard to imagine. We slowed to 1.5 knots with the stern pointed aggressively into the sea. It was as though we had entered a calm harbor of refuge. With the reduction in the yachts motion our situation seemed to be not too bad. We were exhausted and took the opportunity to get some sleep".

Many skippers have commented on the bungee type feel to the boats motion with the drogue deployed. This important characteristic was developed from model testing in the U.S. Coast Guards flow channel, which has glass walls so the underwater motion of drogue models could be observed.

[eric3a]

..

[Retcoastie]

Really interesting reading.

The part that really caught my eye was the “Mooring and Anchoring” section. It all reads well and makes a lot of sense. To temp Mac owners to read it and comment let me quote form the conclusions.

“Fortunately, the more unstable a boat is when tethered from the bow, the more stable it will be when tethered from the stern. Fifteen yours of experience with the series drogue tethered at the stern has demonstrated that, with hurricane force winds and even when buffeted by large breaking storm waves, the boat will ride quietly and will quickly adjust to wind shifts and random wave strikes.
There can be little doubt that a proper stern mooring would have saved many of the moored boats that were destroyed in the four hurricanes that struck Florida in the fall of 2004.”

Now, would this apply to Macs? Probably. On my to do list starting tomorrow is sealing the openings that the shift cables come thru to eliminate or reduce water entering if a big wave comes aboard and fabricating a bridle to anchor astern. I don’t think waves would be a problem because I usually anchor in the lee of an island. I have had some really bad rides due to wind, including anchors pulling loose after hours of weaving back and forth.
What do ya’ think?

[Tiny Tim]

I was reporting above on one successful deployment of a sea anchor in fairly moderate storm conditions. This was my first attempt. The series drogue may well have performed better; but remember I wanted to avoid being taken into the middle of the (Great) lake where I surmised that the waves would be bigger than what I was seeing. Also I did not have a Jordan series drogue onboard. They do sound like a practical invention.

The loads on the sea anchor were large and I contemplated what course of action I would take if the parachute or line failed. My next step would have been to run downhill to the center of the lake dragging a cheap 48 inch canvas drogue that I bought on eBay. I've tried it once before for a test off the bow and it didn't work well to aid pointing. I do suspect that it would work for running bare poled.

I am among those who would be pretty nervous running downwind with big waves chasing me dragging a drogue. So I made that a fall back strategy. Getting pooped is high on my list of fears. My boat is just not sealed up well enough to keep water out of that huge lazarette if big waves come calling. The cockpit is very large too and would hold a fair bit of water.

BTW, with the sea anchor there was no yawing. It did not sail around the anchor. The boat stayed right about where it was supposed to relative to the parachute. I had 175 feet of nylon line out. All I know for sure about this technique is that it is preferable to lying abeam.

I have read an account of a Mac sailor who did lie abeam in 45 knot conditions with the centerboard up and claimed it was only mildly uncomfortable. A 20 degree roll is what he experienced and skidding down the waves. It doesn't sound bad until you experience it. Terrible. He must have had a cast iron stomach. The rolling side to side put me pretty close to the heaving limit. I sat at the companionway where I could see the action. That seemed to help.

I have now installed a Level-o-meter below, so that crew can observe the heel level. I rationalize that if a nervous crewmember knows that the boat's best stability is at 15 degrees and they see it oscillating up to 15 degrees, they'll be less nervous. It feels very different below at 15 degrees than in the cockpit and when it is oscillating fast, having something to monitor the roll might help.

I hope the Davis Rocker Stoppers help to reduce the speed of oscillation. I tried dragging one and it nearly pulled me overboard. Really grips. I think they will help reduce rocking at anchor but whether they will work to stabilize a boat lying to a sea anchor is a tougher question. Next time I get some decent waves I'll try it and report in.

[Frank C]

I have six rocker stoppers to use at anchor. I haven't felt they were much benefit, but absent them, who knows how much worse it would have been.

However, I very much doubt they'd be good in a storm. As you've already discovered, the loads they create are enormous. I discovered that when weighing anchor and trying to motor away, forgetting they were still hanging from the 26X's hip stanchions ... the curved stanchions at the companionway.

I'd worry about the rocker stoppers pulling those stanchions right off the boat. Worse yet, if a line on one side of the hull broke, they'd impose a drastic heel from the other side.