Using an Anchor Buoy in a Tight Anchorage?

[Dockhead]

Originally Posted by Don C L

And this is why around here the custom for many years has been for everyone to set a bow and stern hook. Then there's room for more people and no crashing in the night. I really don't understand the hostility to the practice. But that is fodder for another thread perhaps...

If it's local practice and it works, why would anyone be hostile?

It's nearly always right to do what others are doing when anchoring or berthing anywhere.

I don't like being anchored fore and aft in general because I want my boat to swing with the wind and present less cross section to the wind. But if I came into your anchorage and saw all of you anchored like that, I would do it too. Otherwise I would swing differently and interfere with the rest of you.

[thinwater]

Originally Posted by boatpoker

I can easily pull it apart by hand but hanks for reminding me. I have to pick up another spool

What is the purpose of the twine/float? Just to mark the anchor? Obviously not for recovery. You would still have to dive, and you could not use it to guide a diver down (it would break).



If it is one rode length in front, they already know the anchor is there. If the winds are light and it is elsewhere, they probably won't associated it with your anchor. It's a crab float.

[Franziska]

Originally Posted by thinwater

What is the purpose of the twine/float? Just to mark the anchor? Obviously not for recovery. You would still have to dive, and you could not use it to guide a diver down (it would break).







If it is one rode length in front, they already know the anchor is there. If the winds are light and it is elsewhere, they probably won't associated it with your anchor. It's a crab float.

Apart from that not everyone might get what the floating milk can is...

[boatpoker]

Originally Posted by thinwater

What is the purpose of the twine/float? Just to mark the anchor? Obviously not for recovery. You would still have to dive, and you could not use it to guide a diver down (it would break).



If it is one rode length in front, they already know the anchor is there. If the winds are light and it is elsewhere, they probably won't associated it with your anchor. It's a crab float.

The first part of your question is answered in Posts #50 and #55 and no I don't have to dive, that is answered in post #70

The second part of your question makes no sense, "if it is one length in front" ? ... "IF" ! You have no idea IF it's in front or besides or aft ... see posts #50 and #55 again.

[Dockhead]

Originally Posted by boatpoker

The first part of your question is answered in Posts #50 and #55 and no I don't have to dive, that is answered in post #70

The second part of your question makes no sense, "if it is one length in front" ? ... "IF" ! You have no idea IF it's in front or besides or aft ... see posts #50 and #55 again.

Thinwater can speak for himself, but I would agree with him that from a slight amount of wind, the location of the anchor will be obvious (based on some assumptions about scope). I don't personally need this information from you, as I'm not going to be anchoring so close that plus or minus a boat length or so of anchor chain will make any difference.

If it's crowded and everyone needs to configure for best use of anchorage space, I'll drop my anchor in line with your stern and halfway between you and the next boat, or if it's really crowded -- last time that happened to me was in English Bay, Antigua -- then in line with your bow. So long as I have even very roughly the same amount of scope out that you do, then we will all swing just fine.


Obviously you have more confidence with boats similar to yours and with similar rode. You have to stay further away from power boats, boats on rope rode, etc. But you will see that in crowded anchorages, different boat/rode types flock together. For this reason.


In very light wind if there's no obvious position of your anchor then a floating milk jug will, indeed, look like a crab float, more than an anchor buoy. Maybe if you drew a large anchor on it with a Sharpie. But in very calm conditions you will likely drift over your own anchor at some point and you risk tangling with your own float.

[thinwater]

Originally Posted by boatpoker

The first part of your question is answered in Posts #50 and #55 and no I don't have to dive, that is answered in post #70

The second part of your question makes no sense, "if it is one length in front" ? ... "IF" ! You have no idea IF it's in front or besides or aft ... see posts #50 and #55 again.

I read that, I just don't agree with it.


a. The string does not really help much with the ring idea. Maybe.
b. The ring won't work in many or most cases. You won't agree so we can leave that.

c. The drifting part (you say makes no sense) makes perfect sense to me and most. You just see it differently. The anchor is either where we expect it to be (some boat lengths in front of you, and if we anchored over it, that was intensional) or it is beside you (or some other place) and we're going to assume a milk jug is a trot line float and probably not worry at all about it. Certainly it is not really fishing or anchoring gear. Obviously.


That's OK, it's a forum, and you said what has worked for you.

[thinwater]

Originally Posted by Dockhead

... But in very calm conditions you will likely drift over your own anchor at some point and you risk tangling with your own float.

Heck yes. For cat sailors, it is not unusual to end up anchor backwards, with the rode running between the hulls. Weird, but not that unusual. You drop one leg of the bridle and it swings out. The float line would have to slide right under one of the drives or one of the rudders or both.

[boatpoker]

Originally Posted by thinwater

I read that, I just don't agree with it.


a. The string does not really help much with the ring idea. Maybe.
b. The ring won't work in many or most cases. You won't agree so we can leave that.

c. The drifting part (you say makes no sense) makes perfect sense to me and most. You just see it differently. The anchor is either where we expect it to be (some boat lengths in front of you, and if we anchored over it, that was intensional) or it is beside you (or some other place) and we're going to assume a milk jug is a trot line float and probably not worry at all about it. Certainly it is not really fishing or anchoring gear. Obviously.


That's OK, it's a forum, and you said what has worked for you.

A. The string has nothing to do with the ring. I thought that was obvious.
We attach a heavy line to it. We have successfully used it twice.

B. Assuming where an anchor is a guess at best. as proven by the photos I already posted.I prefer to minimize guess work.

C. I question the intelligence of someone who would drop an anchor on an unknown object.

Do as you will and I will do as I will. This is now getting silly so I'm out. Have a great day.

[Putt-Putt]

Originally Posted by thinwater

Heck yes. For cat sailors, it is not unusual to end up anchor backwards, with the rode running between the hulls. Weird, but not that unusual. You drop one leg of the bridle and it swings out. The float line would have to slide right under one of the drives or one of the rudders or both.

I don’t quite get how this actually occurs.

If there is little force acting on the boat the anchor rode will be hanging vertical, between the hulls someplace near the bow until it rests on the bottom. Unless you are planning to get underway it really does not matter in which direction the anchor lies.

If you do plan to get underway, slowly retrieve about a boat length of rode and the boat will likely swing around to face the anchor without the rode moving from it’s vertical orientation.

If there is significant forces acting on the boat the notion that the boat rides steady, stern to the direction of the force with the rode strung out between the hulls just seems absurd. The only instance that I can think of that this backwards anchoring could occur is if you had no forces acting on the boat and a sudden windstorm rolled in directly from astern. Even then, the chances of the boat keeping its stern to the wind long enough to draw the rode tight seems very slim when you consider the shallow draft of a cat.

As all boats are basically subjected to the same conditions this backwards anchoring should also occur to monohulls. I for one have never experienced or even seen it.

Help me learn. What conditions result in this backwards anchoring?

[thinwater]

Originally Posted by Putt-Putt

I don’t quite get how this actually occurs.

If there is little force acting on the boat the anchor rode will be hanging vertical, between the hulls someplace near the bow until it rests on the bottom. Unless you are planning to get underway it really does not matter in which direction the anchor lies.

If you do plan to get underway, slowly retrieve about a boat length of rode and the boat will likely swing around to face the anchor without the rode moving from it’s vertical orientation.

If there is significant forces acting on the boat the notion that the boat rides steady, stern to the direction of the force with the rode strung out between the hulls just seems absurd. The only instance that I can think of that this backwards anchoring could occur is if you had no forces acting on the boat and a sudden windstorm rolled in directly from astern. Even then, the chances of the boat keeping its stern to the wind long enough to draw the rode tight seems very slim when you consider the shallow draft of a cat.

As all boats are basically subjected to the same conditions this backwards anchoring should also occur to monohulls. I for one have never experienced or even seen it.

Help me learn. What conditions result in this backwards anchoring?

It happens. Not often, but not very rarely. It's happened to me twice. Tide reversal is the normal culprit.

A cat has widely spaced hulls. If the wind goes to zero (or the tide reverses just right) the boat moves over the anchor and comes up tight on the rode with the bridle between the hulls. Just imagine motoring straight ahead, past the anchor; on a cat, the boat will stop and the position is stable. Yes, a monohull would simply drift past the rode and snub up in the opposite direction. But a cat has a 15-25' wide target where the rode goes between the hulls. I think you will find that is more common than you imagine. No, recovering some rode will not solve the problem. And ...

You can't easily recover rode with the rode between the hulls. The angle of the chain wrapping around the roller is too great. You can't power up to the anchor as you should, without risk of hitting the rode with a prop. It's better to spin the boat, as I explained. It's easy.


This is normally more amusing than troublesome. Once, the winds were light and I didn't even notice until ready to leave. No big deal. It's never happened in a big enough wind for the forces to be large, as long as you catch it early, which you should.

[Don C L]

Originally Posted by rslifkin

In places prone to wind shifts or wind from different directions on different days it doesn't work as well. Being anchored bow and stern while sideways to the wind is generally a bad situation. It's also more of a pain to set up, especially for larger boats with correspondingly bigger / heavier stern anchors.

In a place with a steady prevailing wind direction where boats will typically face the same direction then anchoring bow and stern becomes more of an option.

True. And I should add the caveat that my stern hook has about 60 feet of chain and then about 300 feet of nylon line. On those nights when I get broadsided by a breeze or tidal current I have to drag myself out of bed and take the stern rode (nylon line) and uncleat and walk it up to the bow and cleat it off up there. The boat swings to whatever in kind of a Bahamian moor and I go back to bed. If some one is near by I may have to take up the bow or stern rode to give myself space.

[Putt-Putt]

Ok, you provided 2 instances where this might or has happened to you.

One was when the wind went to zero, let's also say that there was no current.
If the wind went to zero that implies that in the immediate past there was some wind and during that time it would not be unusual for the cat to be pointing into the wind at anchor. Then the wind slowly stops. Gravity acting on the catenary curve in the rode would slowly pull the boat forward up until the rode was vertical. Momentum would carry the cat a little bit further, but not far as you then start to reinitiate the catenary. The boat would soon settle with the rode vertical as there are no forces acting on it.
It is quite a stretch to pronounce that the boat then sails past the anchor, comes up tight on the rode and stops, (but remains pulling on the rode,) in a stable position.
I have no doubt that in this set of conditions the cat will come to rest with the rode vertical and all of the rode save the length equal to the water depth plus freeboard on the bottom. What forces would hold it up tight on the rode?

The 2nd condition you cite is in a tidal flow reversal. When the forces imposed on the hull of a normally anchored boat reverse it would imply that the dominant forces are now acting on the stern. This would push the boat forward, but not in a straight line as even the drag of having to relocate the anchor rode from the bottom will impose lateral loads on the bow that would tend to steer the boat to port or starboard. That coupled with the fact that free floating objects always present themselves broadside to the force acting on them does not bode well for your we will end up anchored backwards with our tail between our legs proclamation.

I have no doubt that you have found yourself becalmed at anchor with the rode hanging vertical between the hulls and the anchor is at any one of 360 directions. What I have difficulty with is the instance where you are pinned stern to the dominate force with the anchor off of the bow. That to me just does not happen.

But I could be wrong, and I've eaten my words in the past. Just post a video with the wind at 10+ knots and you anchored backwards & stable with the rode entering the water near the props and I'll belly up to the table.

[Franziska]

Originally Posted by Putt-Putt

Ok, you provided 2 instances where this might or has happened to you.

One was when the wind went to zero, let's also say that there was no current.
If the wind went to zero that implies that in the immediate past there was some wind and during that time it would not be unusual for the cat to be pointing into the wind at anchor. Then the wind slowly stops. Gravity acting on the catenary curve in the rode would slowly pull the boat forward up until the rode was vertical. Momentum would carry the cat a little bit further, but not far as you then start to reinitiate the catenary. The boat would soon settle with the rode vertical as there are no forces acting on it.
It is quite a stretch to pronounce that the boat then sails past the anchor, comes up tight on the rode and stops, (but remains pulling on the rode,) in a stable position.
I have no doubt that in this set of conditions the cat will come to rest with the rode vertical and all of the rode save the length equal to the water depth plus freeboard on the bottom. What forces would hold it up tight on the rode?

The 2nd condition you cite is in a tidal flow reversal. When the forces imposed on the hull of a normally anchored boat reverse it would imply that the dominant forces are now acting on the stern. This would push the boat forward, but not in a straight line as even the drag of having to relocate the anchor rode from the bottom will impose lateral loads on the bow that would tend to steer the boat to port or starboard. That coupled with the fact that free floating objects always present themselves broadside to the force acting on them does not bode well for your we will end up anchored backwards with our tail between our legs proclamation.

I have no doubt that you have found yourself becalmed at anchor with the rode hanging vertical between the hulls and the anchor is at any one of 360 directions. What I have difficulty with is the instance where you are pinned stern to the dominate force with the anchor off of the bow. That to me just does not happen.

But I could be wrong, and I've eaten my words in the past. Just post a video with the wind at 10+ knots and you anchored backwards & stable with the rode entering the water near the props and I'll belly up to the table.

Without wanting to get to deep into this lengthy discussion with you, I can assure you that it can happen.

We had this a few times. I recall two very strong incidences of this which were hard to resolve at the time.

Once in a wind against current situation in the Etel River and once in a tide channel next to Vlieland also with wind against tide.


Do you sail a multihull?

[Putt-Putt]

Well thats interesting, both instances were when 2 different forces oppose each other.

Your experience in that they were hard to resolve seems to differ from others who experienced this phenomenon.

I would like to see a picture of a cat anchored backwards with the rode streaming aft at an angle of attack of about 15º. Go any?

No, I don't sail a multihull, I run a power boat.

[carstenb]

we sail a monohull we have had it happen a couple of times- once the chain wrapped around the keel (really bad news)