I am curious about the rules both formal and informal about using an extra line (with no additional hardware) while racing. As example if you were racing a one design that had no traveler...and a crew member doubled an extra dock line over the end of the boom - pulling by hand...in an attempt to pull it more to center...would this be illegal or frowned on? Thank you.
This is almost 100% time going to be illegal. Almost every One Design (it IS One Design!) rule-set has a clear paragraph near that top that reads like this.
The Beneteau First 36.7 Class Rules shall be interpreted such that Owners participating in one design racing make the
assumption that
no modifications are allowed unless they have been specifically approved by these rules, or by a direct
ruling from the First 36.7 Class’ Technical Committee. This means that any changes or modifications from a standard
Beneteau First 36.7 would have to be specifically allowed within these rules to be considered legal. The penalty for
participating in Class one design events with a boat that had knowingly made modifications outside of those allowed
within these rules could be disqualification from those or any First 36.7 Class one design events.
That's the deal. Unless the One Design rules says you can, you can't.
Now, some very permissive 'One Design' classes will allow changes, mostly in the interest of getting more boats in. I'm thinking like the Capri 25 fleet. But this is rare, and then the boat is not really One Design.
But really, you need to read the class rules.