Here's a quick question when the manual says it needs 115 ft for a halyard is that correct or would 100 ft work?
Short answer: nope. If a line is too short, you can't extend it. If a line is too long, then...
BEFORE you buy anything: Look CAREFULLY at the manual for the specific YEAR of your boat and see how they rigged the halyard (i.e., blocks) and whether it was run aft or not. Then COMPARE that to your boat. Then measure the parts you can get to (mast to cockpit), add the height of the mast (it's in the manual) and then ADD how you're gonna attach the headboard end of the halyard when it is NOT connected to the headboard.
Then double check everything.
I have a shroud mounted cleat that I use to attach my halyard to when not in use. Some use the aft end of their boom, which would require a longer line.
Never depend on anyone else's measurements, use your own.
FWIW, I bought 120 feet and wish I'd made it 5 feet longer.

Your boat, your choice.
