My boat (one of them which is close to a Cat 27), 32ft yacht, 7000lb's loaded, no winch
only a wench
50ft 1/4" chain to 200ft of 1/2" polyester 8 braid with a Model 60 Spade (in alloy 9lb or 18lb in steel). Sat through 45-50kts and the only problem we had was getting it back, it buried rather too well. I do race
occasionally and that is a lightweight set-up. If cruising more I'd go up a size on both. Also those anchors are top end so don't go weight for weight on a plow style (delta included) or it may bite you. I use the alloy version.
There is absolutely no way a 27fter needs anything larger than a 5/16" chain and/or 9/16" warp. The strengths of those is more than enough and piles higher than any matching anchor will hold, even top end ones like the Spades, Supremes or Rocnas. Many cleats
will rip out of decks below those loads as well.
Sure you can carry heavier if you like, some do, but all you are doing is spending more money
on putting reasonably useless weight exactly where yachts don't like it i.e. the ends of the boat. Don't go silly on G40 (hi-test) or high tensile chains, you will get zero benefit from them on your boat. BBB or Grade 30 is more than enough. Save the bucks and spent them on a bloody good anchor instead.
Some like to carry, say 10ft of 3/8" chain thinking the extra weight is a good thing. In a way it is but you will gain better holding power from your anchor with a 17ft length of 5/16" and save weight at the same time. Chain length counts a lot towards how the anchor will perform. Increase the length of chain by 50% and that will increase it's anchor helping power by 100% (actually more like 92% and just rounding here for the ease).
There is no such thing as a 'must be' length on either the rope
or the chain, it all depends on where you anchor. Why carry 250ft when you only anchor in 20ft and equally whay carry 250ft when you anchor in 300ft. Work
on 5 times the maximum depth
you'll anchor in as minimum, 7 times if the weather can get a bit bad or 10 times if the weather can go real bad. But the rule
is 'more the merrier', it's harmless to have to much but dangerous to have too little.
If you have or will get an anchor winch
use Nylon, not as slippery and they work
far better on that. Hand over hand polyester is equally as good if not better. Don't listen to people saying you get more stretch out of nylon as they obviously intend to use their ropes in an overloaded state and well beyond manufacturers recommendations. At normal working loads the difference in elastic elongation (generally known as stretch even if slighly incorrectly) is not large at all, up near break load it is.
I'd suggest 45ft of 5/16" chain to whatever length warp to sut the depths you anchor in.
Anchor wise a 12lb Danforth pattern is a bit small, a good lunch pick size. General rule
is 1lb per foot of boat length then tweak to suit both boat and YOUR happiness level. Big heavy blunt bowed boat with a windage issue go up in size. Lightweight harbour racing
flyer you can go down a size. If big makes you feel happier go big and sleep well. Newer designs like the Spade and it's derivatives you can go down a size as they do have far superior holding power. Or get one of those in the same weight and then drink a bottle of rum
and sleep just well i.e just take the extra holding power bonus.
So I'm thinking a 10kg delta if racing
or a 16 if cruising. Same applies to CQR's and Bruce's as they all hold similar loads depending on bottom type. If you anchor is soft sandy or sloppy bottom types Danforth patterns work well in those. If not like that all the time go for a plow style as they are more versatile. Ideally go for one of the new designs like a 80 Spade, 25lb Supreme or a 10kg Rocna
but be aware they may
cost more in the short term, it all depends on how much you value you anchoring stability.
Don't get caught up too much by the weight differences between the old and the new style anchors, both work on very differant principals. The old work on weight where the new work on surface area. The new ones are refered to in weights purely as many can't get their head
a 600cm2 anchor rather than a 20lber.
Always carry a second anchoring system. You may never need it but do you want too find out the hard way, most don't. The 2nd system can be a bit lighter if you boat in an area replacement gear
is easy to obtain. If not make it grunty as well.
And the last big thing - play with your gear
and find out the best way to use it. Operator error is a large component of many anchoring issues. We see it almost daily where people blame the gear only to find out they run 2:1 scopes or other stuff which shouldn't be done. Short scoping is a big common issue so the general rule for setting scope
is more the merrier but 5:1 minimum on rope
and chain rodes. If you have the room to chuck out 10:1, why the hell not? It's only going to increase the holding a pile more and that's what it's all about. A rode set at 10:1 has a massive higher holding capability than one at 5:1 a pile more than twice.
All reasonably simple and once set-up well you will gain confidence and hence sleep better. Sadly it may cost to get it sorted the 1st time but that's just the price
you have to pay to keep you and your boat safe. No fun lying in a coffin thinking "****, I should have spent that extra $50 to do it right".
My job is specifying anchoring systems. No you can't come and see me, I'm not in your country but if you enjoy a jet plane ride you can and I'll happily buy you a beer
while we yack about anchors and associated gear.
over40pirate - it's no wonder you chain straightens quickly in a breeze, you have next to none. Go all or a fair whack more chain and you'll find it is a very different story. FYI - using such short lengths of chain is pretty much a US only thing. Cruise
further afield and you'll find you are in a definite minority if not almost on your lonesome.