Topping Lift and Sail Shape
Today I went sailing and observed a Hunter 260 with his topping lift very tight so that it lifted the boom to the point that his mainsail never was anything but a flapping piece of fabric on any point of sail. I wanted to pull along side and to suggest to him to slack off so that the sail could take a proper shape, but he was with his girl/wife, so I was afraid that I would embarrass him. Later he put up his bimini and it became obvious that he had shortened the topping lift so that the boom would clear the bimini (but he was attempting to sail this way even before the bimini was raised). With the rig that he had, he will never get satisfactory sailing performance. And, probably in time, he will abandon sailing as being frustrating and unfulfilling.
If you happen to have a similar situation on your boat, take the sail to a sailmaker and get it recut so that the boom will clear your bimini without using the topping lift to hold the boom clear of the bimini. If you sometimes sail without the bimini and want the full size of the sail, then have the sailmaker to put in a flatting reef cringle/reef points on the sail....this is a relatively shallow cringle at the boom/leech end of the sail used normally to flatten the sail, but if done properly for this application, it will lift the boom also.
I'm sure that someone will disagree, but don't sail with your topping lift tight...if you do, you distort the shape of the main sail. Slack the topping lift off so that it does not distort the sail shape....the boat will sail better. Also, never sail with with boom attached to the pig tail wire on the back stay if you have one...the pig tail is to support the boom when sails are down. And if you don't have a topping lift, put one on your boat, but don't sail with it tightened....use it to keep the boom from dropping down into the cockpit when putting up sails.