We recently purchased a used sailboat. One of the things noted on the survey was to replace the main halyard sheave, since it jammed during the survey and the surveyor visually inspected it and saw it was bad. The boat was taken to Dodson's by the previous owner to have the work done. The rigger went aloft and told the owner that there wasn't a problem, and never changed the sheave. We took the boat the following weekend on her shakedown cuise, sailing from Stonington, CT to Marblehead, MA. The second day out, the halyard jammed, along with the boom topping lift. It short-circuited our trip and we sailed the rest of the way under jib and engine. I took it to a very reputable yard in Marblehead (Marblehead Trading Co.) and they changed the two sheaves. The old ones were toast. Don't know how the rigger could have missed it. I sent photos of the sheaves to the General Manager, but my emails have been unanswered. The place may be nice to spend the night and go ashore, but at this point I don't recommend the yard sevice. If I could give it less than one star, I would.