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Old 18-04-2016, 15:33   #1
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Sea Anchor Size

Hello,

I have a 37' foot Rafiki cutter with a displacement of 26,500 lbs.

I want to purchase a sea anchor but I am seeing inconsistent numbers from various sources. Some charts list the boat length and others list the boat displacement for sizing the sea anchor.

Could anyone point me to a good resource for this info?

Thanks.
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Old 18-04-2016, 17:04   #2
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Re: Sea Anchor Size

I'd call the manufacturer and ask their opinion.


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Old 18-04-2016, 17:16   #3
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Re: Sea Anchor Size

Google, How big of a sea anchor do I need?

PS Advisor: Sea Anchor Sizing - Practical Sailor Print Edition Article


Almost same size vessel too.

Basics: Sea anchor should displace 2 x your weight.
If in between sizes go larger
Line should remain taut as possible when in use.
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Old 18-04-2016, 18:06   #4
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Re: Sea Anchor Size

Basically - big.

Too small one is not effective.

Buy quality. My clients had theirs torn in Alex. Not what you want from a piece of equipment that you need in an Alex.

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Old 18-04-2016, 18:15   #5
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Re: Sea Anchor Size

Thanks Jacknest,

I did quite a bit of googling, but like I mentioned that I keep seeing conflicting information.

I like the 2x the boats displacement rule. So that puts my parachute size between 18' - 24'.

The only nagging thing I have on my mind is the recommendation from 'Storm Tactics' by Parady that a slightly smaller anchor is better as it will stir up the water more. This makes sense to me. The boat is bound to drift a bit more with the current, but it should be a smoother/safer ride.

I may not have a choice as I don't see any parachutes between 18' and 24' at the surplus store anyway.
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Old 18-04-2016, 18:26   #6
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Re: Sea Anchor Size

I read that too big can lead to the chute collapsing. This true?

I'll have to settle for best quality within budget. But I did find some military parachutes in excellent condition.
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Old 19-04-2016, 07:15   #7
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Re: Sea Anchor Size

Quote:
Originally Posted by PhaseSpace View Post

(...)

I'll have to settle for best quality within budget. But I did find some military parachutes in excellent condition.
IMHO if you do think you may be using yours in heavy weather, go quality.

You may be OK with less quality if you use yours for fishing stops or similar fair weather stops.

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Old 19-04-2016, 08:51   #8
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Re: Sea Anchor Size

Quote:
Originally Posted by PhaseSpace View Post
I read that too big can lead to the chute collapsing. This true?

I'll have to settle for best quality within budget. But I did find some military parachutes in excellent condition.
Being that a military chute if a personnel chute is designed for a couple of hundred pounds of load in air, and you going to attach tens of thousands of pounds of boat to it, and water is about 800 times as dense as air, I wouldn't think it would be acceptable at all, I know it's done, just I wouldn't want to rely on one myself.
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Old 19-04-2016, 09:42   #9
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Re: Sea Anchor Size

Quote:
Originally Posted by a64pilot View Post
Being that a military chute if a personnel chute is designed for a couple of hundred pounds of load in air, and you going to attach tens of thousands of pounds of boat to it, and water is about 800 times as dense as air, I wouldn't think it would be acceptable at all, I know it's done, just I wouldn't want to rely on one myself.
+1 on the above!

So: Now is when you pull out the list of toys that you want to buy & ask "will this save my life/can I live without it"?
As I can pretty much guarantee that there's a lot more is on most folks lists which fall into the "want" category, & not the "need" one.

But to answer the original question. When in doubt, go bigger.
Also, when you're "searching", several manufacturers have published their equipment's performance data online, free for download. That, & much of it is on here as well.. usually with the links included, to the sources (manufacturers).
The last time I tried searching for it, it took me 2 tries, & 10sec in order to find it.

Plus, of course, you can order hard copies of these books as well. And the data goes back for many decades. With full writeups of each use of said piece of gear; including how it was rigged, boat specs, weather conditions, etc.
So, more than enough, Real data, upon which to base your decision.


PS: When I say "toys", above, read thet to mean Everything in your life.
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Old 19-04-2016, 15:29   #10
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Re: Sea Anchor Size

Go to seaanchor.com, which is Para-Tech's web site, lots of info there.
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Old 29-04-2016, 08:42   #11
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Re: Sea Anchor Size

In their book " Storm Tactics" Lin and Larry Pardey have an interesting take on this idea on the concept of size. If I understand them correctly, they recommend to go smaller, if in doubt. The reason, again, if I understand them correctly, is that they use a sea anchor to a: stabilize the hove-to angle and to b: reduce downwind drift when in the vicinity of a lee shore. Since their storm survival tactic is to create a "windward slick of calm water", requiring the vessel to be slowly drifting downwind through the water, the use of too large a sea anchor reduces the downwind drift to the extent that a windward slick of calm water no longer forms.
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Old 29-04-2016, 10:44   #12
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Re: Sea Anchor Size

talk with jeff hartjoy about drogues an sea anchors in real time.
i think you may enjoy his words.
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Old 29-04-2016, 12:14   #13
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Re: Sea Anchor Size

I did a lot of research and bought a Para-Tech. It is built like a tank! Anything short of this kind of quality is not, IMHO, worth risking your life for. The company is Fiorentino, tell them your boat size and they will recommend an size anchor and line. I have a 30,000# 50 foot mono-hull and bought a 16 foot model. I also had them make a pennant with a snatch block to allow me to shift the position of the boat as it sits on the anchor at sea (highly recommended). Take a look at the videos on their web site.

Dave

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Old 29-04-2016, 12:18   #14
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Re: Sea Anchor Size

For a while I've been vaguely wondering about using a few cone type sea anchors in series like the Jordan.
Maybe 5, 6, 7 of them, around 20 inch diameter, maybe even of differing sizes.
Boat's something over 10 tons.

If the warps were of different lengths would it be reasonable to expect some of them to be in the favoured parts of successive waves and thus maintain a steady tension?

Obviously haven't thought about it in any great depth, just chucking it out there for informed opinions, derision, whatever you like.

I'm too lazy and cheap to build or buy a Jordan is what it is... and no, I don't value my life as much as some
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