Why don't you just loop a line around the base of your upper shroud when you are about to dock? I keep a line there all the time and I hang it on the lifeline when not in use.
Because shrouds, like stanchions, aren't made for that. Shrouds are designed for upward, not sideways, pull. Think about it. Don't do it. Spend anywhere from $25 to $125 and do it right. Sheez...
Sorry for the rant, but I see SOOOOO many stupid boaters out there:
--- docklines run through the eyes of cleats
--- docklines taken with them instead of left on their own docks
--- no midships spring cleats
--- jumping off the boat to run around like idots trying to move their boats so they can reach their cleats instead of staying on their boat and using boat hooks to grab their dock lines
--- as Zee said, bow lines given to stupid idiots on the dock who pull them in hard
--- Please, stay away from me when I'm docking, even singlehanded and it's VERY windy, 'cuz most of the time, if not ALL the time, you mess up a simple situation --- help is, and should be unecessary; it's the skippers role to dock the boat, not the dummies on shore
Sorry for the rant again.