Tug":encbn5oz said:
Have a Anchor Bow roller question....i want to buy a new bow roller , the pivoting, self- launching design so i can deploy and retrieve the anchor while standing up thru the hatch.How do you determine the size, model number , dimensions...for the right bow roller for your particular boat. Thanks Tug
Tug-
Making them fit and also work together with the windlass can be a difficult and somewhat trial-and-error process, and you almost need to take the boat to a marine supplier and fit the bow roller, anchor, and windlass to the boat.
Since this is often impossible or too difficult because of distance or other constraints, I can offer you this advice:
The large pivoting Lewmar bow roller is large enough to handle most any anchor used on a C-Dory and also fits the C-Dorys from 19 feet and on up very well. It's what I use with a Fortress FX-16, and I've seen it work with many other anchors such as the Delta Fastset, the Bruce, and many others. It 's large size and the "drop-nose" action it provides will start most any anchor falling from the stored position.
The other approach would be to just copy a known set up that uses the exact anchor you plan to wind up with. The Fastset and the Bruce will self-launch from some fixed (non-pivoting) anchor rollers, but not all, and the placement of the windlass and the addition of an extra roller between the windlass and the bow roller can be critical ingredients. (The length (and therefore the weight) of the chain between the anchor shank and the windlass can be a factor that's not considered until something doesn't work!)
If you know for sure what anchor will work best where you boat, copying a known combination can be the easiest, but the large pivoting roller will give you greater flexibility in the long run, should you want or need to make changes.
One caveat: the drop-nose or pivoting anchor roller won't be as convenient, however, when just using it in a manual mode, as the drop nose function just gets in the way, since it isn't necessary for manual work, and the rode has to be set very tight to hold it in the up position.
The other, or third alternative, just guessing, and the resulting trial and error process, can be frustrating and expensive, so it's a tough process of choosing, whatever you do.
Others will have an opinion on this, too.

Lewmar KABR-21 bow roller
Joe. :teeth :thup