Mast Tuning
Yes, the leeward shrouds can loosen when you are close-hauled, but since you are new to this boat, if I were you I would ensure that the standing rigging is properly tuned. The following is an excerpt from the North Sails tuning guide for the Cat 22. See the related link for more information. Mast Tuning (Before Sailing) First loosen shrouds until they are somewhat loose. Mast Rake: The mast rake is probably the single most important element of tuning your boat. Note the mast rake should vary from fixed to swing keels with swing keels having slightly less rake. Start with boat sitting on its lines in the water. Hang a weight from the end of the main halyard and cleat off halyard with weight and shackle 12" below the boom. Measure distance from the aft face of the mast to where the halyard crosses the boom. This measurement should be 8" for fixed keels, 6-7" for swing keels. Adjust the headstay turnbuckle to achieve desired measurement. Tighten backstay until snug, no slack. Remove weight from halyard, attach a tape measure to halyard and haul to top of mast. Measure from side to side tightening or loosening upper shrouds until mast is centered. Now start tightening upper shrouds until they have show 28 on the gauge. Tighten forward lowers until they show 24 on the gauge. Tighten aft lowers until they are 24 on the gauge too. To measure shroud tension use a Loos Model A Tension Gauge. The end result here is to have the mast straight fore and aft with a small amount of rake to give the boat some "bite" upwind. Now you're ready to go sailing! Mast Tuning (on the water) Sailing upwind with moderate backstay on, sight up the backside of the mast checking that it is straight. Tighten or loosen lower shrouds until mast is straight side-to-side. Your mast is now tuned for moderate winds. The reason for checking the mast while sailing is that the shrouds will stretch slightly under load. We want to make sure the mast is straight, especially side-to-side, under sail. SAIL TRIM Light Air (0-8 knots) Main: Outhaul should be tensioned so clew is 1-2" in from band. Cunningham/halyard should be loose so there are horizontal wrinkles coming off mast. Traveler should be centered or slightly to windward. Adjust main sheet tension so top telltale is flying 90% of the time. Note: Top batten will be slightly outboard of parallel to boom, this may be impossible in very light wind. Genoa: Tension genoa halyard so that there is a hint of wrinkles in the luff. Be careful not to over tension. Adjust genoa lead fore and aft so luff breaks evenly (roughly 30" forward of deck drain). If top telltales luff first, move car forward. If bottom telltales luff first, move car back. Backstay should be adjusted so you have about 6" of forestay say. Upwind, trim your sail so it is approximately 4-6" away from the end of the spreader. Moderate Air Main: Pull foot out to band-traveler in center. Tension mainsheet so top telltale flies 70% of time; top batten will be parallel or slightly in board of parallel. This helps to generate power. Tension main halyard/ cunningham to just remove horizontal wrinkles in luff. Genoa: Trim sheet so sail is 2-3" from end of spreader. Tension backstay to medium setting. This will straighten headstay and slightly flatten sail (3-4" of sag). If sailing in waves and chop, move genoa lead forward 1-2 holes to generate more power. Heavy Air Main: Outhaul out to band - max tight. Tension halyard or cunningham hard to keep draft forward. Tension aft lower shrouds to keep mast from bending too much. Backstay on very tight. Top batten should be outside of parallel. Traveler should be dropped to leeward all the way. Tension the vang tight enough so that the boom does not go up when the mainsheet is eased. This will allows you to "vang sheet" to keep boat on its feet. Remember, flat is fast. Play the mainsheet aggressively in the puffs to keep the boat flat. Genoa: Tighten halyard quite tight to keep draft forward. Move lead 1-2 holes aft of light air position. Trim sail so it is 3-4" off end of spreader. Tighten backstay very tight to make headstay as straight as possible and flatten sail.
