My Dart 18s have excellent main and jib sheet locking systems. Jib has identical hook as Prindle 15,16,&18 that catches in fing suspended from approx 4/5 up mast ,main has same system as on Nacra 570, the approx 1&1/2 diameter ring hooks on to top of mast where a prong sticks out approx 1&1/2 inches- great systems the sails NEVER come down unless you unlock them! Trouble is you can't get them down when underway especially In storm conditions when single handing the cat! this passed weekend I stupidly got caught trying to outrun a thunderstorm and almost lost it because whenI saw the cat following me about a 1/2 mile astern Had headed back to shore I came about and thought I could run with the wind- Mistake- a 45/50 mph gust hit me and the blocks to main sheet ran all the way out but could not be uncleated! Battens snapping cat going under with both of front pontoons submerged up to and over front beam! Somehow by Devine Intervention she righted and I was headed to shore on one hull- and managed to get to shore but could Not get the sails down as the thunderstorm continued for almost an hour as I rode it out in pouring rain & winds gusting over 40- I could not get my sails down by myself no matter how I tried! dart owners know you have to rotate the mast and simultaneously pull on main sheet to lower it. To lower jib you have to tug on jib sheet line and pull on bottom of sail- not easy in a storm trying to stay on cat that is tied to a float in 5 ft of water in swells oner 3 feet with wind howling! So what I learned from my stupidity is to tie down my sails just Before they lock just like my friend Joe insists I do whenever I rig. His Nacra 570. Ps cleats on mast to tie down to always cause jib sheets to snag so you have to improvise, but it's safer. Pps don't trust on line weather reports storm was supposed to be 2 hrs away, black storm clouds should alert you that discretion is the better part of valor- call it a day and leave the cat on the beach- come back & pick it up tomorrow

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So what I learned from my stupidity is to tie down my sails just Before they lock just like my friend Joe insists I do whenever I rig. His Nacra 570. Ps cleats on mast to tie down to always cause jib sheets to snag so you have to improvise, but it's safer.

word of caution here:
when your main is attached to the hook on top, you are inducing a 1:1 force with downhaul (no mechanical advantage)
when your halyard runs up your mast, and back down to a cleat, you are now doubling the forces by turning your entire main/downhaul into a 2:1 - doubling the forces on your mast - keep that in mind

"Even though you don't see any movement, a traditional main halyard (run up the mast and back down) doubles the compressive load on the mast. A hook or clutch mounted at the masthead, however, does not. Without the turning block (sheave), there is no 2:1 purchase. A 100 kg pull on the downhaul produces only 100 kg of compressive load on the mast."

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Pps don't trust on line weather reports storm was supposed to be 2 hrs away,

We were always taught that weather doesn't have to "move" to catch you, it can form new cells, faster than you can fly, let alone sail.
If the Cat has a bit of weather helm, it should head up. allowing you to drop the sail, a sea anchor tempoarily tied to a bridal helps. We once intentionally flipped the boat, then sat on the side of the hull til a vicious storm blew by.
Of course you need sea room for that.

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Hobie 18 Magnum
Dart 15
Mystere 6.0XL Sold Was a handful solo
Nacra 5.7
Nacra 5.0
Bombardier Invitation (Now officially DEAD)
Various other Dock cluttering WaterCrap
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