Anchors and self-retrieval

[orduna]

Spanner, I enjoyed you reply and support your theory that a good length of chain helps an anchor to hold as it decreases the angle between anchor and rest of mooring line allowing a more horizontal pull to the anchor. However, mooring in 400ft with only 430ft of anchor line (a scope of 1:1.075) suggests to me that conditions must have been very calm with no tidal flow. I appreciate the qualities of a yak, low wind resistance and low-wetted hull area, but I cannot believe such anchoring arrangements would work in many areas. You must have arm and chest muscles like Pop-Eye!!

 

I have read the thread you provided but the messages are mixed, as 100ft of chain or the use of an Alderney Ring certainly cannot be applied to a yak, but it still suggests an adequate scope is desirable. Tests carried out by the RNLI and boating magazines constantly prove that ANY anchor will increase its holding capacity by decreasing the angle between the anchor and the craft and the easiest way to do this is to have an adequate scope of line, or even better a combination of rope and chain – bearing in mind the carrying/load/handling limitations of a yak. However, the folding grapnel, the original theme of my post, still has the lowest holding capacity of any anchor on a weight-to-weight basis, but is easy to stow. It is everyone to his or her own priorities.

[s2vto]

Theory is one thing...

 

get out on a kayak and try it!

[JRT]

GB, that's great, thank you! I'll definately give that a go.

 

Cheers

 

John

[GB]

Anchoring any vessel is more of an art than a science. My anchor setup shown in previous post holds me in 25m of water running at up to 4 knots with bottom of mixed shingle and hard clay only letting out 35 - 40m of warp. The same setup in 10m of water over sand in a gentle 1-2 knot tide sometimes needs the same amount out hence the bruce or danforth would be better for softer composite.

 

As for anchor style, different anchors work in different situations. I would put a wager against the notion that a grapnel is less effective than a danforth or bruce over hard ground.

 

Experiment is the key for kayak anchoring, just as it is for anchoring a boat.

 

How's this for a comparison.

 

On my kayak I use a .75kg grapnel with 1-2meters of 6mm chain with 10 mtrs of 3mm warp and 40 mtrs of 1.2 mm braided line. I can put up to 30lb pull on this when turned braodside to the warp (not recomended unless playing about). My kayak is 14ft x 28inch x 6inch draft.

 

In work I use a 3 ton danforth style anchor with no chain just 40mm anchor wire. On this I can put a 50 ton pull when the winches are fully loaded, this gives a staight pull from barge to anchor. The barge is 40 meters x 30 meters x 3 meter draft.

 

See if a scientist can work out any relation to those figures.

Edited January 29, 2007 by GB

[overrun]

Yes m8 I use the slip method too. I will take a pic and post it up for you, give me ten mins.

 

Ok it was more like 15, I had to get dressed first to go outside

 

The rope on the anchor acts like a trip, the ring will move to the front of the anchor when paddled over. NB the bouy is only for a quick exit from anchoring not for alderney type anchor retrieval.

 

 

Me too with 0.75kg anchor, once set needs plenty of warp for a shallow angle when pulling out, paddle up current. Might be awkward in a strong tide.

[YakDiver]

I use the slip method as well,

as they say so far so good

[spanner]

30 ft excess in 400ft of water is what Davy uses on his boat, but he has a lot of chain weight. In reality I end up with more than that, but usually no more than 100ft unless its windy.

 

Consider this for example. When I caught the skate my GPS showed I was towed 70yds while at anchor, i.e. it held and didn't drag, and I know that cos I ended in the same spot after we released the fish. 70yds is 210ft, and it was 380ft deep, so I had 434ft out, thats an excess of 54ft and an angle at the sea bed of over 60deg rather than the 20deg a 3:1 gives you. In reality I was initially downtide of the anchor so that was probably only 35yds, and I was pulled another 35yd uptide past the anchor, which works out to 394ft! Sounds crazy, but it works.... in deep water.

 

You are correct about needing a low angle to get the best performance from the anchor, but in deep water you do that with chain weight, not warp length. Not many yachts anchor in 400ft, they are usually in shallow bays.

 

The tide run is not insignificant, 1 to 3knts, but another factor in The Sound of Mull is the that there are at least 2 tide flows in the water column. While you may be drifting west in the surface current it may be flowing east on the sea bed where your anchor is. If you try putting out a long warp you will end up swinging all over the place.

[GB]

We get a split level tide in the haven too Spanner, can be quite amusing at times especially if 2 different kayaks are anchored in the same area as they do sinchronised dancing around each other. Me and Stu have had some right laughs in this situation where one of us keeps piroeting around the other's kayak.

[orduna]

30 ft excess in 400ft of water is what Davy uses on his boat, but he has a lot of chain weight. In reality I end up with more than that, but usually no more than 100ft unless its windy.

 

Consider this for example. When I caught the skate my GPS showed I was towed 70yds while at anchor, i.e. it held and didn't drag, and I know that cos I ended in the same spot after we released the fish. 70yds is 210ft, and it was 380ft deep, so I had 434ft out, thats an excess of 54ft and an angle at the sea bed of over 60deg rather than the 20deg a 3:1 gives you. In reality I was initially downtide of the anchor so that was probably only 35yds, and I was pulled another 35yd uptide past the anchor, which works out to 394ft! Sounds crazy, but it works.... in deep water.

 

You are correct about needing a low angle to get the best performance from the anchor, but in deep water you do that with chain weight, not warp length. Not many yachts anchor in 400ft, they are usually in shallow bays.

 

The tide run is not insignificant, 1 to 3knts, but another factor in The Sound of Mull is the that there are at least 2 tide flows in the water column. While you may be drifting west in the surface current it may be flowing east on the sea bed where your anchor is. If you try putting out a long warp you will end up swinging all over the place.

 

Wow! I am trying to get a mental picture of this.

[space monkey]

I could do with a bit of expert advice from you lads regarding anchors, I fish on rock and therefore the method of holding is by snagging and snagging only - approx 40-50 foot of water in average tide conditions. I've made an anchor of about 1 pound with 4 "bendable" prongs, which also incorperates a weak trip. However I only used it once as it was a bitch to pull out and in a strong wind creating a rapid drift it was very un-nerving, if I went with thinner wire I doubt it would hold - I therefore devised a "throwaway" method; basically 3 5 inch nails bent to make 3 prongs, this was tied to a short length of 50lb line, with added weight of a piece of any scrap metal this would hold, but it would break after a while - all in all its trying to find a compromise between holding and safety as you can not put as much pressure on the anchor rope in a yak as you would with boat - any ideas would be greatly apprieciated.

 

cheers space monkey