Surfbird-
Good that you bought 1/2" three strand nylon, because it's what most windlasses use that are sized for the C-Dory.
It will be best if you buy 1/4" G-4 High Test Chain for the same reason.
One of the primary reasons some of us add windlasses, besides for the obvious ease and convenience, is for the safety factor of being able to operate the anchor system without having to go onto the foredeck in bad weather, big winds, swells, river currrents, lightening, and especially when operating alone. Also, if you're going to use the motor to position the boat caefully, or take up the slack when hoisting, you have to be at the helm, and cannot be on the foredeck at the same time.
To this end, I don't like windlass systems that require the operator to go to forward to release some chainstop, snubber line, or other lock/catch mechanism.
A good, appropriately sized (or oversized) windlass with a strong pivoting bow roller will work to lower, raise, and store the anchor and rode without extra tie-off devices.
I will agree that one ordinarily doesn't want to leave the rode tension on the windlass, and it's best, especially in heavy weather and overnight situations to tie the rode off with a snubber line to take the tension off the windlass. However, for daytime use when moving about here and there, such as when fishing, I want the system "push-button simple" from the helm, period!
To this end, I'd recommend a very strong, robust windlass that is even oversized for the boat.
I have a Quick Aires 500 windlass on my 22 which is brutally strong for a boat the size of a 22. When I experienced some occasional slip and difficulties passing the splice, I did two things:
1. First I added 100 feet of 1/4" G-4 chain at the front to replace the shorter 15 ft section, and thus enable me to anchor most of the time without even getting to the splice, (all chain works best for me in reservoirs and river anchoring situations anyway), and
2. I also re-invented the wheel by developing a different type of splice where the change in diameter at the splice-back is not so abrupt. (See
HERE)
These changes worked so well for me here on Lake Shasta that when I added a windlass to my 26 1/2 ' Sea Ray, I installed a Lewmar Horizon Express Windlass (similar to the Horizon 1500 with a slightly higher gear ratio), 30 feet of 5/16" chain, and 200 feet of 5/8" 3-strand nylon. With the enormous pull available in the windlass and a huge anchor locker, I selected the 5/8" line because it fit the windlass gypsy better than smaller diameter lines, and did not present a storage problem. Otherwise, 1/2" would have been fine, and would have provided a more elastic/shock absorbing rode. I may still go over to 100 feet of chain up front, depending on experiences with the present rig.
One thing that must always be mentioned when discussing anchoring and equipment is that the specific types of anchors, rodes, and windlasses that will be best for any boat owner's use will be different depending on their area of use and anchoring/cruising style. What works best on the Columbia River may well be quite different from that one would be best in the sunken, underwater, and glascially carved rocky canyons of SouthEast Alaska. YMMV
HTH- Just another $0.02 of morning advice and jabberwocky for the offering!
Joe.