Anchoring for a Storm

[maxingout]

Originally Posted by BigCat

No, thanks, it's the tiny, repulsive, mosquito-infested mud-lined mangrove hole for me. I would have said that there would have been quite a few of those within a half day's sail from there. I'd be looking for a place so small that hardly anyone could drag down on me, because hardly anyone else could fit in there.

Places like you describe did exist in Puerto Rico, but unfortunately in the real world of hurricanes and tropical storms, a hurricane hole that was big enough for one well-secured yacht quickly filled up with ten boats. Everyone has equal access to your hole in the mangroves, and the tiny hole will be chock-a-block with boats of all descriptions. Your harbor of refuge becomes a row of dominoes, and when one boat goes, the whole row may go.

I was on a Navy base, and it wasn't legal for civilian yachts to come into the harbor in a storm, but that didn't stop the onslaught of "illegal" yachts. They poured into the harbor and overran the most protected anchorage in the Naval Base. Many of the boats that crammed themselves into the best areas had woefully inadequate anchors and ground tackle.

I agree with your point. The problem was that it didn't work that way in the real world.

[BigCat]

Re: Mangrove hidey-holes

Read this- http://www.jarogers.com/marilyn.htm

I have hidden out in such places in Guam and in the Philippines during typhoons (aka hurricanes, tropical revolving storms.)

I would have gone to Culebra or Vieques. We are talking small holes where there isn't room for many waves nor much distance to drag. Don Street says there aren't any decent hurricane holes in Puerto Rico.

[maxingout]

Originally Posted by BigCat

Re: Mangrove hidey-holes

Read this- Hurricane Marilyn at Culebra Puerto Rico

I have hidden out in such places in Guam and in the Philippines during typhoons (aka hurricanes, tropical revolving storms.)

I would have gone to Culebra or Vieques. We are talking small holes where there isn't room for many waves nor much distance to drag. Don Street says there aren't any decent hurricane holes in Puerto Rico.

When I did my internship in the Panama Canal Zone, I met a trimaran sailor named Harry Abbott. He and his family were cruising in a self-built trimaran - as I recall the name of the yacht was Antigone. He had his trimaran in Culebra during Hurricane Hugo in which there were over 200 yachts destroyed. He lost his yacht there inspite of the presence of mangroves.

"Of approximately 300 boats in Culebra when the storm hit, maybe 50 survived," said Dabney. "And that means they had damage but could be repaired. We found our boat on the beach, all the windows blown out of it and water inside. We were lucky."

Hurricane holes: Safety from the storm?

Culebra was always considered the ultimate hurricane hole when I lived in Puerto Rico.

I met a cruiser in New Zealand who had his boat sink in a typhoon in Guam after another yacht dragged down on him and punched a hole in his hull.

Hurricane holes are hard to come by when you need them the most!

[SCCatSailor]

Dave - I like your suggestion of two anchors spread at 45 degrees to windward of other boats, but here's my main concern - I have to anchor in a river with a tidal current, so it will switch directions at least once before the strong winds come. Have you had any experience with that situation - where the anchors had to reset themselves? I would think that the two anchors spread at 45 degrees would have as good of a chance of resetting as a single anchor (or maybe twice as good that at least one will reset!).

Also, with this set-up, did you attach both rodes to a single bridle or did you try two spearate bridles? It would seem that two could potentially tangle as the boat swings and really mess things up. Thanks for all the help.

Steve

[BigCat]

Originally Posted by maxingout

When I did my internship in the Panama Canal Zone, I met a trimaran sailor named Harry Abbott. He and his family were cruising in a self-built trimaran - as I recall the name of the yacht was Antigone. He had his trimaran in Culebra during Hurricane Hugo in which there were over 200 yachts destroyed. He lost his yacht there inspite of the presence of mangroves.

"Of approximately 300 boats in Culebra when the storm hit, maybe 50 survived," said Dabney. "And that means they had damage but could be repaired. We found our boat on the beach, all the windows blown out of it and water inside. We were lucky."

Hurricane holes: Safety from the storm?

Culebra was always considered the ultimate hurricane hole when I lived in Puerto Rico.

I met a cruiser in New Zealand who had his boat sink in a typhoon in Guam after another yacht dragged down on him and punched a hole in his hull.

Hurricane holes are hard to come by when you need them the most!

Yes, there is always the danger of too many boats for too few spots. I don't disagree at all that unattended or poorly run boats to windward are a very important danger.

Mangroves by themselves aren't enough--you need a small, sheltered cove as well. The cove part is more important than the mangrove part. I'd pick shelter from waves over shelter from wind, though shelter from wind is very important-the best hurricane holes have high ground all around as well as shelter from waves. Some anchorages in Culebra have a long fetch from some directions. Obviously, one is looking for a minimum of fetch from all directions, since hurricanes can be unpredictable, and even loop-the-loop sometimes.

Martin's formula of wind pressure gives you something to think about-wind pressure in pounds per square foot = wind speed in (statute) miles per hour squared x .004-@ 95 pounds per square foot in 154 mile per hour winds. A person standing must present something like 6 square feet. Even a hefty lad like me weighs less than 570 pounds, so in a worst case hurricane, you could actually blow away like cartoon cows aloft in tornadoes.

The wind hitting my BigCat 65 from the side in a blow like that would generate a load of 20 tons. -I don't know how to quantify the force of waves if you have a large fetch, but obviously, you have very large loads if the waves are big and breaking. It would take at least two of the FX-125 Fortress anchors to windward, or the equivalent, and at least 1" nylon rodes, to resist that. That would be so expensive -say $5,000-that I am going to make over-size Bugel type anchors out of aluminum, so that I can carry enough anchors to have a good shot at surviving a maximum hurricane in a decent anchorage.

[maxingout]

Originally Posted by SCCatSailor

Dave - I like your suggestion of two anchors spread at 45 degrees to windward of other boats, but here's my main concern - I have to anchor in a river with a tidal current, so it will switch directions at least once before the strong winds come. Have you had any experience with that situation - where the anchors had to reset themselves? I would think that the two anchors spread at 45 degrees would have as good of a chance of resetting as a single anchor (or maybe twice as good that at least one will reset!).

Also, with this set-up, did you attach both rodes to a single bridle or did you try two spearate bridles? It would seem that two could potentially tangle as the boat swings and really mess things up. Thanks for all the help.

Steve

The two anchors at 45 degrees worked well for me because of my special situation at Roosevelt Roads Naval Station. The harbor was open to the southeast, and the storm surge, swell, and large fetch meant that I had to put all my cookies in the southeast basket. There was good protection in all other directions.

The bottom was mud and sand, and the holding was excellent, so I never had a problem. Those were the days of my Westsail 32, and I had the anchor rodes going port and starboard out through the "hawse pipes" in the forward bulwarks.

When I purchased my catamaran, I went to a bridle like you see in the drawing on maxingout.com. I never ran more than one anchor on the bridle. If I did a hammerlock configuration, it would be off one of the bows, and I wouldn't activate it unless we were in real trouble - dragging.

I always had trouble with shifting currents and winds when I had my 60lb CQR because in challenging conditions, the anchor might not reset with a shift in current or wind. Then I was in trouble.

That's why I finally went to a 70lb Buegel anchor in Australia. It handled shifting winds and currents without a problem. I have a friend on a 51 foot custom south African catamaran, and he uses a 100lb Beugel anchor with good results.

If I was in your situation, I would probably set my FX 110 off the bow with flukes at a 45 degree position which is perfect for mud, and I would put the 70 pound Beugel off the stern. That would tether the yacht fore and aft which would probably work well on Exit Only. In less severe conditions we often used the Buegel 70lb off the bow, and an FX37 off the stern with good results.

[maxingout]

Originally Posted by BigCat

Mangroves by themselves aren't enough--you need a small, sheltered cove as well.

National Geographic published a picture of mangroves rolled up like a carpet after Hurricane Andrew went through south Florida.

It showed a giant roll of mangroves that had been uprooted and rolled on itself. After looking at the picture, I decided that there wasn't any place that is 100% safe in a category 5 hurricane. When the mangroves roll up in a ball, you might as well kiss your yacht good-bye.

[BigCat]

Originally Posted by maxingout

National Geographic published a picture of mangroves rolled up like a carpet after Hurricane Andrew went through south Florida.

It showed a giant roll of mangroves that had been uprooted and rolled on itself. After looking at the picture, I decided that there wasn't any place that is 100% safe in a category 5 hurricane. When the mangroves roll up in a ball, you might as well kiss your yacht good-bye.

Well, I have seen mangroves growing in rather exposed places as well as in sheltered coves, and I'm sure you have, too. I would think the rolled up mangroves would have been in a fairly exposed place. If you can find a well sheltered spot and have lots of big anchoring gear, even category 5 hurricanes might well be survivable, based on the math. Obviously, large debris (including dragging yachts) would be a big danger even to the well prepared voyager lucky to have a good harbor. Not many of your neighbors would be well enough prepared for that level of force-100 psf or more. No amount of anchoring gear would save you in that level of force if you were in an open bay like the one off of the base you mentioned, even if you were upwind of the other yachts, if the wind blew from offshore.

[Tropic Cat]

Avoidance is the best defence. I trust that anyone with a boat in the water in Louisanna or Mississippi is being hauled out as we sit here and type. Plan B would be the 4 day trip to Houston, Tx.

Both plans are achievable with the time available and although they can't guarantee the boat's survival, they certainly will improve the odds.

[BigCat]

Originally Posted by rickm505

Avoidance is the best defence. I trust that anyone with a boat in the water in Louisanna or Mississippi is being hauled out as we sit here and type.

Well, there have been cases of boats in boat yards going down like dominoes in hurricanes. Obviously not multihulls, but you don't want a mono falling onto your multihull.

[Dudeman]

I must admit I have little experience using an anchor sailing. But as a climber I use anchors all the time. Here is a diagram of the force that is applied to two anchors when equalized at different angles. This link
is very informative.
climbing anchors

[Tropic Cat]

Let me revise my earlier post. Those nice folks at the National Hurricane Center as of their 11:00PM update, are now suggesting that folks in Houston need to be making plans to avoid IKE. The predicted track has changed.

What can I say ... it's a hurricane.

[cats..paw]

Originally Posted by freetime

Good luck, take some pics on your boat when she is ready for ike... Sounds scary with this hurricanes, we don´t anything like that over here.

Thanks, freetime. We prepped the tri for Hanna (thinking TS, possible H1) and secured everything but did not strip the boat, knowing that we can return if something bigger comes along later.
Took some pics. Not sure yet how to best post them.

What's your weather like now...temps, winds, seas?

Cheers.

[delebash]

I live on Virginia's Eastern Shore (Delmarva Peninsula) and have had to deal with five or six hurricanes with three different multihulls: a 30 ft Piver tri, a 40 ft Marples tri, and a macgregor 36 cat. For all of the storms, we have been at home and familiar with local waters. Although Horne Harbor (as someone mentioned earlier), on the Wicomico (Reedvillle) would be awesome, it is across the bay from me. My strategy is the same as the mangrove strategy. Take the boat up a creek and find a clean bank alongside a stand of trees. Pick a space in the creek that has the least fetch to closest timber stands. I use 5/8 polypropylene, at least 2 100 ft lengths (its cheap). Tie your bow, stern and spring lines (poly) to some big trees near the bank. Then put out at least two, maybe three breast anchors on your normal rodes and make them as taut as you can pull them. I try to suspend the boat at least 8 to 10 feet off the bank. The distances mean that you can make all the lines really tight and still not have to worry about the tide making up really high. This method has worked fine everytime including some 70 mph storms. But hey, its always a crapshoot about how much weather or tide that you are going to get.
I live on Pocomoke sound and watched my old piver (after I sold it) sit out a 70 mph westerly sustained wind (measured 8 miles away at a NOAA installation) for over an hour on a 33 lb cQR on a bridle with a three mile fetch and what looked like 6 to 8 foot waves. Amazingly, it never dragged. It just goes to show how important a bridle is on a cat or tri. There is no hunting or yawing, it just holds the boat straight to windward. By the way, I have kept all three boats on a mooring made of three large danforths aligned at 120 degrees with all chain with a diameter of about 75 feet. This has worked well even with the many summertime squalls. I wouldn't leave the boat there for a hurricane however. Find some shelter to cut the wind down (like up a creek).

[svcattales]

Originally Posted by SCCatSailor

Dave - I like your suggestion of two anchors spread at 45 degrees to windward of other boats, but here's my main concern - I have to anchor in a river with a tidal current, so it will switch directions at least once before the strong winds come. Have you had any experience with that situation - where the anchors had to reset themselves? I would think that the two anchors spread at 45 degrees would have as good of a chance of resetting as a single anchor (or maybe twice as good that at least one will reset!).

Also, with this set-up, did you attach both rodes to a single bridle or did you try two spearate bridles? It would seem that two could potentially tangle as the boat swings and really mess things up. Thanks for all the help.

Steve

Steve,

I use RickM's system with 3 or 4 anchors. We have lived in Florida for 25 yrs and have done many hurricane drills here and two in the Chesapeake (including Isabel). Our biggest dilemma was always Where is the hurricane really going, Which side are we going to be on, and Where will the strongest winds come from? By the time we were really sure where the storm was going, it was usually too late and too windy to do all the preps necessary. That's why we like the 3 or 4 anchor system because it allows for wind coming from all directions and sometimes it really does.

Our criteria for a hurricane hole is fairly tight creek or canal with small fetch in all directions. Hills on both sides are a big plus, but short fetch is most important. (A long fetch will allow big waves and the dynamic loads on your anchors will tend to wrench them out.) When we find "our spot" we decide which direction has the worst exposure and that is the direction we place our biggest anchor on all chain rode. Then we put our other anchors in two or three more directions. We use a single bridle and lead all rodes to it. When our boat is riding on one anchor, the other rodes must have a little slack in them so we can swing 360 degrees without the keels or rudders "tripping" over them. We put a kellet on each of the nylon rodes to keep them submerged when the boat swings over them.

At our home port we prep the boat in a canal that is too narrow to swing. In this case, we put anchors out bow and stern and run spring lines across the canal to large screw-in anchors. The boat stays oriented in one direction with the bow facing our worst exposure.