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Old 23-06-2010, 15:22   #31
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Originally Posted by SaltyMonkey View Post
That is absolutely NOT correct about the difference between a sea anchor and series drogue. A sea anchor / rode SHOULD allow elasticity and movement through a wave by the bow just as you are proposing a series drogue does in your explain. You need to make sure you choose the correct size of sea anchor and rode.
This elasticity is what results in damaged rudders and parted lines while riding to a sea anchor, and are two of the problems that the series drogue was designed to fix. The third being large damaging forces transmitted to the boat. Evan's website reviews that issue. Roth's book gets into that also.

People who have used both the sea anchor and the series drogue report radical differences in the ride, all from how the braking effect differs between the two. The sea anchor brakes much harder, thereby transferring much larger loads to the boat. The essence of the series drogue is the reduction in forces to the boat. The cones slide through the water much more than any nylon rode can stretch, yet brake enough to prevent pitchpoling.

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Originally Posted by SaltyMonkey View Post
In either case, a passive defense from the stern of a boat is highly dangerous unless your boat is designed in means to be defended in this way, and even then it is suspicious. The stern of a boat (incl cockpit), unlike the bow, is not designed to take on breaking waves at sea as you suggest; moreover the mass is not distributed to the bow of the boat and the windage correct to be able to make the stern of the boat face into the waves automatically and without risk of massive swamping or rolling. This is especially true in a cross sea. It's irresponsible to suggest otherwise.
I agree to a certain extent; nor have I ever suggested otherwise. But many boats have used the series drogue with great success, greater success than sea anchors in fact, which suggests that it can be used with many boats. I'm fortunate to have a steel boat that offers great strength, even in the stern.

Here are some reports about the use of the series drogue: http://www.jordanseriesdrogue.com/D_2.htm

Here are the designer's comments about your concerns

Series Drogues and boat design
With a series drogue deployed, a well-designed and properly constructed fibreglass boat should be capable of riding through a Fastnet type storm with no structural damage. Model tests indicate that the loads on the hull and rigging in a breaking wave strike should not be excessive. Many sailors are reluctant to deploy a drogue from the stern because they fear that the boat may suffer structural damage if the breaking wave strikes the flat transom, the cockpit and the companionway doors. The model tests do not show this to be a serious problem. The boat is accelerated up to wave speed and the velocity of the breaking crest is not high relative to the boat. The stern is actually more buoyant than the bow, and will rise with the wave. However, the boat may be swept from the stern. The cockpit may fill and moving water may strike the companionway doors. The structural strength of the transom, the cockpit floor and seat, and the companionway doors should be checked at a loading corresponding to a water jet velocity of approximately 15 ft./sec.

When a boat is riding to a series drogue no action is required of the crew. The cockpit may not be habitable and the crew should remain in the cabin with the companionway closed. In a severe wave strike the linear and angular acceleration of the boat may be high. Safety straps designed for a load of at least 4g should be provided for crew restraint. All heavy objects in the cabin should be firmly secured for negative accelerations and drawers and lockers should be provided with latches or ties which will not open even with significant distortion of the hull structure.

http://www.seriesdrogue.com/vs/
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Old 23-06-2010, 15:43   #32
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The problem with theoretics is that the nature of weather is never linear. Waves will not always be coming from one nice direction for you to lie stern to with a sea anchor or oversized drogue. As the weather shifts and additional fronts deploy, waves and winds will come from different points and this will affect the positioning and strategy of your boat.

Sea anchors do not do damage to rudders or cause catastrophic stresses if deployed correctly and if distributing load correctly. This may be a more modern approach than Hal's or Evan's review. But sea anchors are not without certain requirements. They do work best on boats that are well balanced and have a traditional design and medium to heavy displacement. This leaves out most fin boats with spade rudders. This might be the citation. And again, going to weather on the foredeck is dangerous once the seas get beyond a certain condition.
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Old 23-06-2010, 15:54   #33
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Originally Posted by SaltyMonkey View Post
going to weather on the foredeck is dangerous once the seas get beyond a certain condition.
In theory (which you scorn as I do) this may be true. But in real world practice I strongly disagree. I have NEVER been in a situation where I felt going on the foredeck was too dangerous. And you have no business deploying a sea anchor if you will not go on the foredeck because the rode will certaintly need to be checked for chafe and perhaps adjusted.

I don't think you have earned the title of seaman if you feel the foredeck is too dangerous. You may have to crawl but you should be able to work there in pretty much any condition.

The whole sea anchor vs drogue thing has been debated endlessly and some people seem to take one POV as religion, when in fact they are just simple tools to help manage waves. If you ever take the time to deploy and recover all three options the trade-offs become immediately clear.
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Old 23-06-2010, 16:20   #34
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...
I don't think you have earned the title of seaman if you feel the foredeck is too dangerous. You may have to crawl but you should be able to work there in pretty much any condition....
I'm sure a lot of dead seaman who earned their titles trying would agree with you.

But alas most did not ride a 700 ft aluminum craft
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Old 23-06-2010, 16:43   #35
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Heave to guys, I think the main question here is how to survive big seas, not who's got the biggest B's.
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Old 23-06-2010, 17:12   #36
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But alas most did not ride a 700 ft aluminum craft
?? sorry, to use your word from a previous post . . . that seems a specious comment . . .what does a 700' aluminum craft have to do with what we are discussing here??

Which was whether the OP should go with a drogue or Para-anchor? And I am pretty sure we are talking about a sail boat less than 100', and most probably less than 50'.
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Old 23-06-2010, 17:34   #37
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Nothing...just questioning your comment re the over-important title of "seaman". Testosterone titles mean absolutely nothing. All you can do is know your boat. And more importantly, know your limitations and let your crew fairly and without judgement know theirs. After a point, going forward on a "small" boat to "set" a sea anchor becomes risky - whether you crawl or you float. That's all I'm saying. But, I'm coming from a solo's perspective and experience. That's all.

Checking for chafe is another animal. no doubt about that
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Old 23-06-2010, 21:23   #38
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It seems that if you NEED to deploy a sea anchor due to the danger your boat is in and are afraid to crawl to the front of your boat due to the danger you would be in, well, you may not be a seaman. I'd be willing to to live with out the title, if I lived through the storm. But, hopefully I have enough balls to get the job done.
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Old 23-06-2010, 22:25   #39
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The question should be "How did you get into this situation in the first place?"

But since you're up there, can you please fix the furler?
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Old 24-06-2010, 04:43   #40
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I was trying to make two pretty simple points:

1. if you set a set anchor you need to be able to go to the bow to inspect the rode from time to time. If you don't feel comfortable going to the bow you should certainly consider other alternatives, like a drogue.

2. if you are going offshore you need to be comfortable moving all around the boat in almost any condition. Early in our offshore sailing we had a furling sail come partially unfurled in the middle of a storm in the gulf stream (very bad routing on my part, but something I learned from). If we had not been able to go forward we would have lost the rig.

We have a few miles and as I said previously, we have never been in a situation where I considered going forward too dangerous - if you take the proper care - crawl when necessary and always one hand for yourself.

The boat (And drogues/para-anchors/rodes, trisails, storm jibs, etc) need to be cared for and looked after, and the crew needs to stay in touch with the changing situation with wind and waves. Sitting below and just waiting for it to end is only giving you about half the chance that being active and in touch will give you.
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Old 24-06-2010, 06:41   #41
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Quote:
Originally Posted by SaltyMonkey View Post
The question should be "How did you get into this situation in the first place?"

But since you're up there, can you please fix the furler?
Valid question and a pertinent point.

But if I was sailing in a time/place where I had a chance of encountering a storm of a magnitude that would require the use of a drogue or sea anchor or whatever poison you prefer, I would not be using a furler or at the very least the sail would be off the furler and stored below before it hit the fan.
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Old 24-06-2010, 09:11   #42
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Originally Posted by estarzinger View Post
I was trying to make two pretty simple points:

1. if you set a set anchor you need to be able to go to the bow to inspect the rode from time to time. If you don't feel comfortable going to the bow you should certainly consider other alternatives, like a drogue.
The question is timing and size. It's a whole lot easier going forward in 50-60 kts than 70-90 kts on a 47 ft aluminum vs a 24 ft Dana in a confused cross sea. A drogue is not an option.

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The boat (And drogues/para-anchors/rodes, trisails, storm jibs, etc) need to be cared for and looked after, and the crew needs to stay in touch with the changing situation with wind and waves. Sitting below and just waiting for it to end is only giving you about half the chance that being active and in touch will give you.
This is true, but again it's still a matter of strategy of when and how you will make your rounds and maintenance. Prepare early. Validate when you can, not because someone dictates a ridiculous maxim such as "You need to feel comfortable in all conditions".
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Old 24-06-2010, 09:13   #43
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skipmac: You are right on about stripping the furler and prepping ahead.
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Old 24-06-2010, 10:02   #44
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crawl when necessary and always one hand for yourself.
I use a 6 point system for moving about the deck under sail. 2 hands, 2 feet and 2 cheeks. Through years of diligent training my buttocks have become much like pseudopods and I am able to scuttle about the decks like a Shaolin master using cheeks only.

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Old 24-06-2010, 10:22   #45
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I eat lots of BBQ to make sure my cheeks are big, round, and giant suction cups.
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