Anchoring on the beach: A new(?) technique

[Salish_Explorer]

Hello, just wanted to share a technique that I used the other day with significant success (more on that in a minute), which I think solves two dilemmas often faced by Dory people: swing and shore accessibility.

I inadvertently tested this out in a ~20mph onshore winds overnight and it worked really well. Video link here: https://photos.app.goo.gl/g9UrvCcsSsTzJnid6

Caveat: This technique is new to me, and I don't see it mentioned prominently on the forums, I'm sure others* have used something like it. There's nothing truly "new" under the sun!

Basically the technique is this: Set an anchor offshore before beaching, then use it to haul your vessel back offshore after, but trailing a bow line, so that you end up in a zero-swing double moor.

I've attached a basic diagram, and will drop the steps in a comment.

The difference between this and a standard shore tie is the ground tackle, and the fact that you are able to bring your boat back off the beach.

Sailors or those with more anchoring experience will recognize this as a modified Bahamian Moor.




*I believe that Marco Flamingo has used a similar technique except with an elasticized section of rode, which 'springs' his boat back off the shore.

 

[Salish_Explorer]

The specifics:

(1) The anchor is readied on a bight - the rode is passed through a shackle (or ideally a swivel) on the anchor, then both ends are made fast.

(2) Approaching the beaching site, just outside the intertidal zone, the anchor is laid off the stern of the vessel. Scope is paid out on both legs of the bight so that the rode trails astern (clear of the prop) as you continue ashore; The anchor is set by briefly halting the scope and powering-on, before continuing.

(3) At the beach, One end of the bight is taken ashore; the other is made fast to a bow cleat. A second rode is also made fast to the bow, and coil taken ashore.

(4) When ready, push the boat off and haul in the working end of the anchor bight. This hauls the boat back offshore. When the boat is hauled to proper scope (3:1 etc), make the anchor rode fast, then haul in the second rode until the boat is 'suspended' between the two points. Make the second anchor rode fast and crack a beer.

Obviously there are two 'issues': first, you need a lot of rope - two full length rodes, at least. This is because, when going ashore you will need to set your scope plus the distance to the shore, times two! On steep shores this is no problem, but in a flat bottom bay may be tricky. Second, you gave to carefully track your rode payout/haul-in, since you will have to verify your scope from shore.

I think this is best suited to 16 and 19-foot CD's, because they can use smaller rode, and thus comfortably carry more. Personally I am planning to set up a dedicated 300' spool of 3/8 on the stem rail specifically for this.

 

[rogerbum]

I've seen a similar thing done with a stretchy rode to the anchor.

 

[colbysmith]

I'm not sure this provides any advantage to anchoring off the bow and stern tying to shore. :? Except maybe in regards to current or wind direction hitting the boat abeam... Colby

 

[ssobol]

The other issue I see is the boat getting hung up in the lines if the current or wind change direction.

 

[Foggy]

My understanding of this 'Bahamian moor-like" off beach overnight anchor system
while you try to sleep swating gnats, the boat moves around as the wind, current
and the tide changes. This causes the anchor rodes to twist, chafe, and/or snag
on anything protruding under the hull (keel, props [like yours is in the water], etc)
in anything much past near perfect weather conditions.

I would not attempt off beach anchoring without first double checking weather
and tide information. I would not secure the boat stern to the seas.

For overnight beach anchoring, I prefer to
1. Secure a single bow anchor (or two bow anchors on a "Y" bridle), either attached
to their individual chain/rode of choice, then a flexible "Anchor Buddy" * (West
Marine),
2. back the boat stern to the beach raising the engine(s) en route and stretching
the bow Anchor Buddy to a depth I can hop off the boat
3. tie a prepared stern anchor line to a stern cleat, toss ashore or near shore, set
the stern anchor maintaining tension on all anchor rodes, hop off the boat
4. off load items for the night
5. release/retie the now heavy tensioned stern anchor line to place the boat to an
appropriate slack tide depth**

To re-board the next day, haul in the tensioned stern line, on load items/anchor
as required, lower and start engine(s), retrieve bow Anchor Buddy, rodes and anchor(s).

Remember what you forgot on the beach before too long underway.

Aye.
* 4,000 lb working load, can be doubled
A 22' C-Dory hull is about 3,000 lbs per specs
** This may take some adjusting to have some tension on the entire bow/stern rides

 

[ssobol]

... (or two bow anchors on a "Y" bridle) ...

You have to watch the angle of the "Y". The wider the angle the less holding power of the anchors. It is possible to have two anchors in a "Y" that have less holding power than a single anchor in line with the boat (normal anchor position).

 

[Foggy]

A Bahamian mooring has the 2 anchors set at about angle of say 180 degrees,
the widest angle possible, which is commonly used.

A bridled "Y" would have the anchors set at a more acute angle, not approaching
180 degrees. A "Y" bridle 2 anchor set up (less angle) is not a "T" 2 anchor set up.

And, with a single anchor set up, the anchor pivots, sometimes significantly, in
response to a vessels movements around it.

So, what is the angle to be "watched" for best holding off the bow with 2 anchors
on a bridle?

Aye.

 

[thataway]

I have used a variation of this technique for many years for dinghies. I have a dedicated anchor chain/rope rode, and set this well out off the beach. At the end of this is a block with the "endless" shore line going to it. I usually tie the bow to the one end, and the other end to a stern cleat. This is especially good in high tidal ranges, so you can tie the boat well off the beach, and still get it back as the tide goes in or out. Length of each component depends on the anchoring depth.

I do not consider this as a Bahamian Mooring. The Bahamian Moor is two anchors at 180* and best utilized where the current or wind shifts regularly, and the boat is riding bow into wind or current most of the time. (except at high and low slack water). Having a swivel at the interphase of the two anchors, especially if the anchors have all chain rode. If not, as Foggy notes, you will have a lot of untangling to do.

The Danforth has been used in a 3 anchor system for storms--each anchor being set 120* from the other. This was first described in the 1930's (and could be even older than that.). If doing thisI would want to oversize each of the anchors. The boat is going to be pulling sideways and I tend to pull the anchor out..

I normally carry at least 3 "Bow or primary" anchors. More recently a spade, or shovel type (Ronca, Manson supreme, Mantis), a Danforth/ Fortress type, and a fisherman/Northill pattern type. On long distance cruising boats there would be way oversized. (Need good windless to handle these heavier anchors)
If I wanted to reduce swinging, I would position the anchors from 20* to 30* apart.

 

[Salish_Explorer]

quote="colbysmith"]I'm not sure this provides any advantage to anchoring off the bow and stern tying to shore. :? Except maybe in regards to current or wind direction hitting the boat abeam... Colby[/quote]

Well, the first big advantage is that in the situation you describe, you have to dingy ashore, whereas here you can beach, then haul the boat back offshore. If you're not carrying a dinghy, stern ties and all other anchor methods are off limits... unless you like to swim!

A second advantage is the one you note - it allows the boat to pivot to weather. I think this is a pretty big advantage, given how much water a boat anchored stern-to-weather can take over the stern (I read somewhere here that a dory was at one point sunk in this situation).

The other issue I see is the boat getting hung up in the lines if the current or wind change direction.

My observation setting it up and watching it all afternoon was that with the motor up, The flat bottom actually slides perfectly over either rode. Which actually makes sense: consider that sailors (including myself) using Bahamian moors have no problem even though they have keels and rudders below. A sailboat can spin around a Bahamian moor all day with no issue being getting the rodes a bit twisted.

I have used a variation of this technique for many years for dinghies. I have a dedicated anchor chain/rope rode, and set this well out off the beach. At the end of this is a block with the "endless" shore line going to it. I usually tie the bow to the one end, and the other end to a stern cleat. This is especially good in high tidal ranges, so you can tie the boat well off the beach, and still get it back as the tide goes in or out. Length of each component depends on the anchoring depth.

I have also seen this, and was partly inspired by it! Again I think the difference (advantage) with setting both at the bow is that it presumably handles an onshore breeze much better. The 20 mph blow that came up when I was anchored out would have put quite a bit of water in the boat if she was held stern-to (and stern-down, no less).

I do not consider this as a Bahamian Mooring. The Bahamian Moor is two anchors at 180* and best utilized where the current or wind shifts regularly, and the boat is riding bow into wind or current most of the time. (except at high and low slack water). Having a swivel at the interphase of the two anchors, especially if the anchors have all chain rode. If not, as Foggy notes, you will have a lot of untangling to do.

I agree that this is not strictly a Bahamian moor, since as you note, it only uses one anchor, and substitutes a shore tie for the second. But the effect is exactly the same - suspending the bow of a vessel between two points, so that it swings within a boat length only and never pivots (backs) its anchor. And if you set an anchor ashore, which you certainly could, I think it definitely would qualify. But anyway, that's why I called it a 'modified' Bahamian!

I would note that from personal experience, tangling is actually not a huge deal. In crowded anchorages on my sailboat I'll set a Bahamian moor about half the time, because it takes almost no extra work and is fantastically secure. A swivel is nice but not strictly necessary, and all-chain is certainly not. If your boat spins, your rodes will twist, but only at the top. It's simple enough to undo - just free the bitter end of one rode and unwind it. I think after a particularly spinny night on my sailboat it took me ten minutes. :smiled

 

[Salish_Explorer]

A bridled "Y" would have the anchors set at a more acute angle, not approaching
180 degrees. A "Y" bridle 2 anchor set up (less angle) is not a "T" 2 anchor set up.

And, with a single anchor set up, the anchor pivots, sometimes significantly, in
response to a vessels movements around it.

So, what is the angle to be "watched" for best holding off the bow with 2 anchors
on a bridle?

Two anchors set in a 'Y' configuration is called a picklefork moor. While the Bahamian is ideally set parallel to weather/tide, the picklefork is set perpendicular to it, and is generally considered stronger. You don't have to 'watch' the angle, however, because it's impossible to lie with the load perfectly distributed. Instead, you lie primarily on one, with the other checking your swing/tacking.

In almost any drag scenario, if either anchor drags the 'Y' simply becomes more acute, with the second anchor progressively taking up the load. In practice, however, properly sized modern anchors set with sufficient scope basically don't drag unless they get backed - which is exactly why either a Bahamian or a picklefork is so secure.

What really makes them secure though is the fact that either one drastically reduces the chance of either anchor getting 'backed' and having to reset - as you mention, the boat never swings wildly around the anchor below, but instead is confined to loading it from an optimal angle.

The one major exception with either is if the weather gets perfectly parallel to your set and the upwind anchor drags into the downwind anchor, fouling it.

You have to watch the angle of the "Y". The wider the angle the less holding power of the anchors. It is possible to have two anchors in a "Y" that have less holding power than a single anchor in line with the boat (normal anchor position).

This is technically true, but in sand or mud if the system overloads and one or the other anchor drags, it will simply drag the configuration into a more acute 'Y'. As the second anchor progressively takes the load, the dragging anchor is unloaded and (unless it has flipped or become fouled) can reset - so the problem effectively solves itself.

Also the 'more secure' single anchor is a hypothetical that can really only exist in a vacuum. In the kind of weather that could drag a properly set double-anchor configuration, most boats will be swinging pretty wildly (significantly increasing the chance of collision in an anchorage), and may very easily find themselves in an abrupt, high-load backing situation (extremely insecure).

 

[Foggy]

Acknowledgements:

Some confusion as the post is about off-beach anchoring; boat stern secured on
shore tied off or anchored ashore in the shallows with bow anchor in deep water.

Bahamian moor language is not applicable to this situation as pointed out.
'Modified Bahamian mooring' and 'Bahamian mooring-like' may be an invention of
the poster as is the term 'picklefork' applied to a "Y" anchor bridle (the picklefork
term not found in modest Google search regarding same).

Again, below, this wild swinging, collision, and high load backing on anchors does
not really apply to intended mild weather off-beach anchoring, the intended
subject matter.

In the kind of weather that could drag a properly set double-anchor configuration, most boats will be swinging pretty wildly (significantly increasing the chance of collision in an anchorage), and may very easily find themselves in an abrupt, high-load backing situation (extremely insecure).

Aye.
PS:
For an interesting and thorough discussion on does/don'ts of Y bridles, snubbers,
bridle sizing/line length for catamarans and more, see below refs:
https://www.snubberhead.com/anchor-snub ... dle-design
https://www.snubberhead.com/catamaran-anchor-bridles

 

[Salish_Explorer]

Some confusion as the post is about off-beach anchoring; boat stern secured on
shore tied off or anchored ashore in the shallows with bow anchor in deep water.

I think there's still some confusion. The post does not refer to a stern tie. It suggest a way of securing the bow only, on the basis that it may have some advantages (and potentially some disadvantages) over a stern tie.

Bahamian moor language is not applicable to this situation as pointed out.
'Modified Bahamian mooring' and 'Bahamian mooring-like' may be an invention of
the poster as is the term 'picklefork' applied to a "Y" anchor bridle (the picklefork
term not found in modest Google search regarding same).

Yes, 'modified Bahamian Moor' is the name I attached. For clarity's sake I referenced the closest common moor, rather than calling it 'Willy Wonka's Super Chocolate Shore Tie Setup'.

Mooring includes anchors, shore ties, and for that matter dock ties. Whether what I've suggested is or is not similar enough to a Bahamian moor to warrant reference to that type of moor is a bit pedantic really. In function it's extremely similar, in that you use two anchor-points to create a single, non-swinging mooring.

As to a picklefork, I can only assume that like a fair bit of nautical vernacular, it simply may not appear in Google, however it is not my 'invention.' It is referenced that way by Brian Fagan in his book 'Staying Put!: The Art of Anchoring'. Others may or may not use that term - again, so long as we can agree on the function of the system on question, it's pretty arbitrary.

 

[thataway]

I agree with Foggy. A point that Salish_Explorer is missing is that Danforth anchors or any anchors are designed for a load pulling straight back in line with the shank of the anchor. If you side load--which his "technique" does, it side loads the anchor and will guarantee it will pull loose and drag or worse with significant load. A C Dory 16 or dinghy is not a significant load. 20 knots of breeze is just a good sailing breeze for some of us--not storm conditions. 50 to 60 knots of breeze, is significant.

I have more experience than I like anchoring in storm conditions; up to 90 knots of breeze on several occasions. (fortunately those two were in calm seas.). I have dove on the anchor rode and anchors in 90 knots of wind, to watch the dynamics. I have also had to deal with anchoring in winds up to 120 knots--fortunately not my boat--during a hurricane. This had to do with random anchors on a 60'
Schooner, anchored in our bayou, which was dragging all over the place and causing damage. During the eye of the storm, we boarded the boat, got power on and secured it to pilings where it was secure and not damaging any other boats.

Salish_Explorer mentions a sail boat, but no explanation of the size draft etc. Also if the outboard is fully up and out of the water, then the ropes of this type of moor will slide right under the boat. If the outboard is down, there is a fin keel, or spade rudder, then big trouble as the rode fouls these appendages.

Just because you tie a line to the stern, does not mean that there is any load on the stern, the boat can still ride to the bow. All of this depends on how one configures the lines.

On my inflatables which I have moored this way, the bow attachment is a line eye spliced with a thimble and a shackle hiding this to the metal bow eye. All of this is to avoid chafe. How is chafe handled on your 16' C Dory?

You equate the C Dory 19 to the 16, it is more relevant to the 22, in that the 19 is basically a 22 with 3 feet of length removed. The pilot house windage, and profile is similar.


Anyway--your technique is not unique, but one does need to be sure his boat is safe.

Thanks for the thought provoking thread.

 

[Salish_Explorer]

On my inflatables which I have moored this way, the bow attachment is a line eye spliced with a thimble and a shackle hiding this to the metal bow eye. All of this is to avoid chafe. How is chafe handled on your 16' C Dory?

You equate the C Dory 19 to the 16, it is more relevant to the 22, in that the 19 is basically a 22 with 3 feet of length removed. The pilot house windage, and profile is similar.

That's good to know.

As to chafe, my experience is that for single-night anchors in moderate conditions on relatively light boats it isn't really an issue. I've used adjustable bridles and sections of hose around the line on larger boats, but all that seems a bit overkill here. The rope path is quite smooth, and even after the rough night in the video above, there was no evident wear.

Have you experienced otherwise?

A point that Salish_Explorer is missing is that Danforth anchors or any anchors are designed for a load pulling straight back in line with the shank of the anchor. If you side load--which his "technique" does, it side loads the anchor and will guarantee it will pull loose and drag or worse with significant load.

I don't mean to be contradictory, but I Believe it's physically impossible to side load an anchor from a single point of attachment.

Two (or three or twenty) simultaneous forces applied to a single point inherently sum to a single vector/force. Side-loading would occur if the anchor was held in place and loaded at an angle - but since a marine anchor is by definition free to reorient, that condition can't occur - even if a second or third line of pull is added, the anchor can simply pivot into line with the sum vector.

I am not an engineer, but Think about a carabiner on the end of a rope: If two people pull on the carabiner in different directions - say 30 degrees apart - they don't side-load the rope.

From a physics perspective, I think the actual concern is that when the rode is fed through the anchor shackle, the anchor effectively becomes a pulley, which can as much as double the force placed on it.

However, adding a vector along the sea-bed (in addition to the 30-ish degree angle of the surface-leg) creates a sum vector that is more parallel to the sea-bed than the vector of the surface-leg alone - ie, it shifts the line of pull closer to the anchor's axis of maximum strength, not further away from it.

I'll be honest and say that I don't know if that's enough, in a truly heavy weather situation, to fully balance out the additional force applied. However in a moderate weather situation it worked extremely well.

As to tangling - you can argue from theory, but I'm speaking from significant practical experience with dual moors when I say it is almost never issue, even without a bridal, even with a fin keel and spade rudder. This is because on any two-anchor setup, as you swing into line you automatically unload the downwind rode, which (with 3-strand) sinks, forming a catenary and allowing the swinging keel to clear. I'm not saying it doesn't happen, but in my experience even on fin-keeled boats it's fairly rare.

If there are any engineers on the forum I certainly would be very happy to be proved wrong on any of this (so long as I can learn something in the process :lol.

 

[thataway]

I don't mean to be contradictory, but I Believe it's physically impossible to side load an anchor from a single point of attachment.

The Danforth and Fortress Anchors are notorious for not resetting and dragging when the direction of pull is changed. This can occur with many situations, such as a 180* wind or current change. I have seen this happen in multiple circumstances, including several where I have broken into the boat and been able to get the engine (es) started and properly reset the anchor thus saving the boat. There are multiple videos and anchor tests which show this tendency, not only with the Danforth type, but at times with other even 3rd generation anchors..

Setting an anchor is an art. You don't just drop it, put a little power against it and then move on to your next stage. You let the anchor sit, then gently put a load on it, check, let appropriate scope out and then more power, until you are certain it will not drag in that direction. Take bearings, and GPS positions with circle of shin if on one forward mooring (more modern) readings of the swing and set a protective alarm.

. The rope path is quite smooth, and even after the rough night in the video above, there was no evident wear.

Marine weather predictions are just that, predictions, and not certainties. I have seen many cases where 20 knots became 30 then 40 and on up. Many boats were lost in the 1982 Cabo San Lucas storm because of that factor. A friend nearly lost his Valiant 40 when he was riding to a stern anchor and the 5/8" double braid line almost chafed all of the way thru. I can cite many other examples. If I am running a line which needs to run thru a block, then it is run thru a block, not thru an anchor shackle.

Bahama moor, failure: In the tidal Río Aranjuez, Puntarenas, Costa Rica, a Columbia 34 cut its rode tangling its anchor rode in the running gear (Martec Prop) and drifted down river during the night. Granted I always set anchor alarms, and usually get up several times at night to check the bearings and rode. I also had instruments over my head in the berth which showed: Wind velocity, Wind direction, compass direction, boat speed over ground and depth, with alarms set on these perimeters. Not necessary in a C Dory, because all of the instruments are there by the helm to check at night. But I still get up several times to check the anchor, bearings etc. Also one should take bearings on a safe passage out of a harbor in case you have to cut and run in the middle of the night. (Yep had to do that twice in my 70+ years of skippering boats.)

As to tangling - you can argue from theory, but I'm speaking from significant practical experience with dual moors when I say it is almost never issue, even without a bridal, even with a fin keel and spade rudder.

. I have found tangling to be an issue. It is possible you have more experience than I have...,

 

[Salish_Explorer]

I don't mean to be contradictory, but I Believe it's physically impossible to side load an anchor from a single point of attachment.

The Danforth and Fortress Anchors are notorious for not resetting and dragging when the direction of pull is changed. This can occur with many situations, such as a 180* wind or current change. I have seen this happen in multiple circumstances, including several where I have broken into the boat and been able to get the engine (es) started and properly reset the anchor thus saving the boat.

Sure. I've seen warnings of the same. That's quite different from side-loading, though, which can break an anchor's shank or flip it out of the ground.

In any case I think it's instructive to look at the context: two anchor moors specifically *prevent* a 180° change - they specifically restrict the line of pull to the direction of set, or very close to it.

I think we're in a situation where we are "agreeing at cross purposes". We both agree that a reset or significant angle change could be problematic - and I think we both agree that a two-anchor moor typically (not in every situation but most) projects against this.

I have found tangling to be an issue. It is possible you have more experience than I have...,

Again, as to tangling, I think we actually largely agree. It can be an issue, it's not typically a major one, all exceptions duly noted and so on...and in any event C Dories don't have keels! :lol:

With anchoring as with any part of seamanship, it's possible to go round and round for weeks, to the eventual consternation of all involved.

Somewhere along the line we left the original setup far behind, though. I'm still very interested in thoughts on it.

From the input so far, if side-loading isn't a concern and the opposing-anchors setup protects against significant directional changes, the real question is whether the pulley effect is an issue, or whether it's mostly canceled out by the improved angle of pull.

I do also hear the question of riding gear (chafe protection), but I guess what I would ask is whether that isn't somewhat outside the realm here. At some point in the name of efficiency, you have to put a limit on how many layers of protection you're going to build in, and say, 'if the conditions change radically, I'll go out and change the gear.'

I can't say exactly where that sweet spot should be, but if anything it's another bright mark for double-moors of any type: You have two entirely redundant systems, from anchor to cleat.