anchoring in water 500m+ deep

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I want to anchor in nice blue water in the med , but it means I have to be out away from the coast in water sometimes 500m deep or more. I tried a parachute anchor but a total pain and boat yaws thru more than 90 degrees. So next thing is to see if we can anchor normally off the bottom.
Questions arising

1) We'll just extend the anchor chain with octoplait (?) as it seems fairly light but with equal breaking strain. I have 100m of 12mm chain and 250 metres of 22mm octoplait. The boat weights 30tonnes but as i said, it's only for day anchoring. Honest. I reckon 20mm might be fine for just day anchoring. Or what?

2) Any ideas of rope suppliers who could sell me a roll of say 500metres? The chandlers all price it up per metre, but i need a roll or two. Any ideas?

3) For a tight day anchor one wd normally use three tims depth to keep yawing to a minimum. But for depeer anchoring - the formula must change? I hope so. I succesfullly anchored in 70 metres with only 100metres out. Yep, a day anchorage again. That old 3x or 5x depth etc must be irrelevant for long long depths? I i might have to guinea pig this - no prob cos of course i can drift a few miles before hitting france or corsica. Unles they drift on to me i suppose...Any other exp/ formulae out there?
 
Very interesting - I wonder whether it's worth thinking a bit laterally and using much lighter equipment than normal - a smallish anchor and (for ease of storage), perhaps a few lengths of thick cord or even webbing (20mm webbing has a 500+kg breaking strain) and you should be able to get that amount for 20 quid per hundred metres.

After all with all that length then the weight will add up. I can't see anything that would hold well in a strong wind or current but in calmish weather then you might be fine.

But hauling it back up - hmm...what was that clever motoring method mentioned on another thread a month or two ago?

Carrying on in my rather silly train of thought I wonder what is the cheapest disposable solution, something along the line of heavy brick and string?
 
Do you have a starboard tack?

How about a flashy auto pilot that will keep you on a GPS point. Backwards, forwards, bit this way ,bit that way.
 
Another solution to anchoring in nice blue water - empty several bottles of blue ink over the side and swirl it about a bit...............................................

What happens if the bit of Med you want to anchor in is 1500 meters deep?
 
Yep, you need a DP system to keep you in position. Just a matter of fitting a couple of azimuth drives and a box of tricks to control them, plus you get another neat screen to play with over lunch
 
Hmmm, I reckon it could be a bit of a handful heaving up an anchor from 500m down. Plus it could bring in a giant squid with it and make a mess of your nice tekdek. No, best way is to run shorelines out: one from Antibes and t'other from Cap Corse. That'll keep you steady for lunch!
 
Why not try using two parachute anchors set at 45 degrees to the boat (one to port and the other to starboard). This will be a whole lot easier than having to mess around with all that extra rode and will stop the yawing.

Alternatively use fore and aft sea anchors.
/forums/images/graemlins/wink.gif
 
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Why not try using two parachute anchors set at 45 degrees to the boat (one to port and the other to starboard). This will be a whole lot easier than having to mess around with all that extra rode and will stop the yawing.

Alternatively use fore and aft sea anchors.
/forums/images/graemlins/wink.gif

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Talk about "knitting". How do you propose to get the sea anchors to stay put? Ground anchors /forums/images/graemlins/cool.gif
 
I reckon that if you throw what you already have off the bow, you will never see the difference as to whether it touches bottom or not. The friction of the line and chain through the water will do just the same as if you were actually anchored. If you want to be additionally secure, you could attach the sea anchor to the anchor chain - maybe to where your chain attaches to the octoplait. I am pretty sure you would feel as if you were anchored. I am also pretty sure that I don't want to be around when you try to haul it up.

However, you really want to consider whether it is worth anchoring in such deep water for just a day. I can understand buying all the extra gear if you were going to stay overnight, but for day anchoring it seems a bit pointless.

One alternative is to lay a mooring, so you don't have to haul in all that line every time you want to go out there. I would also explore the possibility of trying to find a pontoon, but this depends a bit on your need for electricity and water. The idea of shorelines is interesting in theory, but I think you might be too far from shore for this to work. As far as I am concerned, shorelines are a bit like VHF - "line of sight". If you can't see the shore, I would forget the idea of shorelines.

Good luck and let us know how you get on.
 
DO remember that you'll need 5 * depth!

Now, how much space will 2500m of wet octoplait take up and what will it weigh? And assuming that you can lay and recover it at 1 m/s do you realise that laying and recovering your anchor will take almost an hour and a half? I suppose the crew doesn't have anything better to do at lunchtime anyway!!!
 
I have no personal experience of para-anchors but in an other site I red that some boats use a bridle , a second rope tied to the para-anchorline about one boatlength forward and the anchor line tied to the bow and the second to the side so that the boat lies in a small angle to the anchor line. That should keep the boat still.
 
2x depth would be fine but I'm not sure about the day anchoring bit - could take the windlass a few hours to recover it all................ /forums/images/graemlins/laugh.gif

only reason I can see for anchoring a boat all the way out there would be if you were concerned about the perceived quality of your te(a)k decking........... /forums/images/graemlins/blush.gif
 
I bought a 100 meter coil of 28mm three strand, they sold it to me by weight, it worked out at 90p a meter, direct from the suppliers in italy! But where??? I will try and find out! Genoa I think.

But are you sure you want to do this?
 
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Best bet would be to lower the water a bit.

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Do you mean that he should pay to the officials to keep the Gibraltar dam open during the lunch hour ?
 
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