Cruising in the West Country, France, Ireland in a 30-footer -- how much chain do I need? Obviously you can never have too much, but what's prudent? Most people say 30m but it doesn't seem a lot. What think?
I think 30m is a good compromise, though having 50m of 16mm rope above it is highly desirable.
In practice most anchorage in the UK will normally be within 10m at high tide, so 30m of chain will suffice. Even in the Channel Islands you will get away with this in most regular anchorages except at Chausey, though a little more is desirable if you plan cruising there.
If you do not have a windlass, then raising a 20kg anchor in 10m of water represents pretty much the maximum for a reasonably fit man. Extra chain risks back injury. Extra chain also imposes a serious weight penalty on the yacht, right at the bows.
You need to look at the tidal range of the places you plan to visit. If all chain then the minimum accepted scope is 3 x depth - but in France (depending where) the depth can change v.significantly over 1 tide (as much as 10m nr the Channel Isles?). So tide + draft + minimum required depth under keel + a metre or so to get to the deck means you probably need 40m or so. If you aren't going to those parts with such a tidal range you could cut this down or consider a chain/warp combination.
Andrew, thanks for your advice but your mention of a 25kg anchor awoke another concern. My boat is a 30-foot wooden Holman ketch built in 1969. The anchor has "25" embossed on it and I assume this refers to pounds since I can swing it fairly easily with one hand. The boat has done a lot of cruising without getting into trouble but a 25-pound CQR does seem to be on the light side. Am I worrying unnecessarily?
Anchor in 8-10 metres then add 5 metres for tide x 4 scope (heavy weather) and "bingo" +/- 60 metres.
Also - comment on "backing it up with rope" - who ever has end of chain available in a hurry to bend on a length of rope??!!
Personally always make sure that the "bitter end" is well shackled to strong point and last few metres are well marked so that I stop whilst I still have a couple of metres left in the locker.
Other side of coin with a lot of chain is NEVER be tempted to drop anchor in deep (>15 metres) water with chain. Did it once after hitting some good fish in 35 metres of water and nearly broke my back getting it (35 metres x 8mm) back on board - and that was with a windlass!!
I agree. On my Eliz 30 we carry a 30lb Danforth with 50m of chain - once I put the whole lot out in Tobermory harbour, where the depth is a fairly uniform 20m. No fun at all pulling it all up by hand! However that tackle has done fine all over the West Coast of Scotland, so it is certainly adequate.