Anchoring question

[davel]

Out in the Solent yesterday afternoon. Sailed across to Woolton Creek and laid out the anchor, 10 mtrs chain and about 20 mtrs warp in 3mtrs of water. The tide was running west at about 2 knots whilst the wind was from the west at about 6 knots (gentle wind against tide).
I found that I continually veered and eventually sailed over the anchor (no sail set!) finally settling with the warp leading back from the bow of the boat, around the fin and then to the anchor. I was thus held more or less side on to the tide. This happened on two occasions (and has happened before) and the warp always seems to lead out the the starboard side of the boat (coincidence?).
I ended up re-setting for a third time and running the engine in reverse with the minimum of revs. Here the boat sat perfectly happily facing into the tide without veering at all.
Can anyone offer any opinions about what's going on or make any suggestions to avoid in the future?

Dave L

 

[Mirelle]

Think you know the answer already

Wind over tide! A fin keeler will wander around a lot and stands quite a good chance of collecting her warp round her keel; a long keeler will sail straight uptide until she is brought up by her warp, on the "wrong" side of her anchor, she will then meander around until she restarts the process.

The windage of the boat, with no sail set, is greater forward than aft.

With long keel boats, lashing the tiller over or leading the warp off one bow or the other to give her a sheer often helps; fin keels are less predictable but it can work.

 

[Chris_Robb]

Why not use a weight down the the anchor line, to stop it floating up betwenn your fin a skeg? Worked well for me years ago. It wont stop the boat wandering all over the place, but at least you won't get caught up in your own line.

 

[Twister_Ken]

Too much scope

With a good hook on the end, 10 meters of chain would have done. Wooton Creek is pretty sticky holding.

With 30 metres of scope, I don't suppose the neighbours were very amused.

 

[Twister_Ken]

PS - your boat – anchoring fore and aft

Did you start out by laying the anchor up tide, or up wind? Sounds like a sailing boat should have been tide ridden (2kt tide vs 6kt wind) but it's one of those situations where knowing your own boat's characterisitics counts. Probably a shallow draught boat with high topsides would be wind ridden, whereas a deeper draught and less windage would mean tide ridden. Given room and motivation laying a second anchor off the stern to keep her fore-and-aft to the current may have been the answer. Or lying to two anchors (both over the stem) one upwind and one uptide - this is still a good way to wrap your keel though, unless you're using all chain.

 

[davel]

Re: PS - your boat – anchoring fore and aft

I laid the anchor uptide and dropped back with the aid of the motor. I'd have thought the boat's position would have been dominated by the tide - she's a fin keeler drawing 1.8 mtrs without excessive windage. She was certainly facing into the tide rather than the wind (which was very light).

On refection, I think your idea of using all chain (all be it on a relatively shart scope) was probably the tactic to use. The weight of the chain would have prevented too much "sailing over". I guess the other option would have been to lay out a kedge.

Anyway, all the additional activity helped me operate within government and EC regulations by limiting the amount of time availabe to consume beer!

 

[tonyleigh]

I echo what Chris_Robb suggests. I have a bilge keeler and anchor quite a lot often in spots where wind and tide dispute! After a few unpleasant occasions trying to unwind warp which has gone behind a keel and doing its level best to broadside me I invested in a "chum". My technique now is to use minimum scope (6ftms 3/8 chain then warp) for shorter stops but to get a good night's sleep I slip the chum down the warp so it drops almost perpendicular to the sea bed. Seems effective.

 

[Guest]

Two choices depending on a your preferences.

Either increase your water or air drag
If you prefer to lie to the tide drop a large bucket or better still a sea anchor over the stern. This should insure that you lie to the tide (sometimes a part inflated rubber dinghy full of water will do the trick)
If you prefer to lie to the wind set a "steadying" sail from the backstays (off mizzen if you have one) should lie to the wind. The the problem with a steadying sail is that they can be noisy.
Of course you can have hours and hours of enormous fun trying to balance one against the other so that you lie exactly as you warned.
Off course a good weight (the same weight as the anchor) suspended from the anchor cable at about 1.2 X the depth of water will stop the head s swinging around

-{)>

 

[davel]

Thanks to all for comments and suggestions. If you're still following this thread then I have a follow up question on the use of a chum. Assuming the anchor and chum are deployed in a wind against tide situation, what's the effect when the tide changes? Does the anchor tend to stay in position (ie the boat effectively pivots around the chum)? Or does it (as I suspect) depend on the circumstances/forces involved)? What are your experiences?

 

[tonyleigh]

Yes - to both questions I guess. The advantage of the chum is perhaps in that it controls the slack close to the keel(s). When tide works against wind, or when the tide turns, and the keel tries to dance around the warp, there just ain't nothing for it to snag. The stronger the tide or wind the less effective this will be but then the less need for this particular benefit as the hull won't be riding up. Don't know if anyone wants to try a more technical explanation?