During a regatta, 4 Grumpy Old Men on a J-24 were neck and neck on the first upwind beat with against a really talented sailor when the old guy on the foredeck notices that the forestay is no longer attached. The clevis pin had fallen out. When asked, the skipper/owner of the boat said he didn't have any spares on board, nor did he have a screw driver.
Fortunately, the Genoa had a Cunningham and the Cunningham hook fit the forestay. We managed to line things up and stuck the hook in place and finished the day.
Years before I was sailing on a C&C 29 in really lumpy windy conditions on an overcast and cold day. I was on the tiller while the skipper was helping to rig the boat. Just before the start I said, "Here, Terry, you take the tiller" and handed him the tiller which was no longer attached to the rudder post. I sat on the cockpit sole trying to keep the rudder from slamming around too much while the rest of the novice crew got sails down. Eventually we found a roll of duct tape and managed to tape it back together and limped home. It was the closest I ever came to getting seasick, decked out in foul weather gear and sitting on the cockpit sole.