Jan, you have chosen a great anchor. I use the size 6 (22kg) Super Sarca, (but the Excel was not out when I got mine), and although it looks a bit agricultural, by crikey, it works. The Excel is supposed to be as good or even a bit better in holding power, so in my view, (and experience, with these type of anchors as well, you might say), I don't think you need worry about a double system in your case. It does not sound like you are planning world cruising, so a good primary set-up is the way to go. It would be expensive to try and replace your bowsprit, and as you say it is not wide enough for two full sized rollers side by side. My advice is get the appropriately sized Sarca roller assembly, and maybe mount it slightly off-centre for reasons explained below. Then if you don't have hawse pipes either side of the bow to pass a snubber sling through, ie one from each side meeting at the chain hook, then you can just pass a single snubber out under the retaining bar to hook it on the chain. With a Sarca and all chain rode, for what you are planning to do, I doubt you'll ever need a second anchor they are that good, but if you ever do, Benn's method of attaching it in front of your main anchor with a few extra metres of chain is probably the best way. That or having an anchor buddy to place on the rode and let down. I actually modified my bow roller assembly before I bought the Sarca, so don't have one of theirs, as I got a hinged assembly and fitted it inside and in place of the original old bronze one because it had no retainer, and the damn CQR I later replaced used to sometimes jump out of the roller and dent the gun'l. Actually, what I do have is a smaller secondary single roller alongside the main, (hence the mid-line offset idea), which in most (light) weather situations I pass the snubber over, to avoid the hassle of passing it through he main roller, (and a possible jamming if up anchoring in a hurry or at night), and you could probably do that also. 20cm would cope with that I think - compare with my pics below, especially if you don't have a hawse pipe each side of the bow to allow use of a snubber bridle. In all the years we've been anchoring, on only one occasion was that secondary roller not up to the task, and I just dropped the snubber into the space between it and the main roller assembly when it blew up, rather than muck around in the dark trying to pass it through the main roller. Interestingly, that same blow saw a yacht nearby jam its snubber hook, and therefore the anchor chain as well, in the bow roller, trying to do a quick up-anchor because it was dragging, and they ended up aground....
Oh, and yes - old pics, so I have taken one swivel off now.
