I tried using a spinlock on my H-18 when they first hit the market a few years ago. It was really cool for the roundup at the leeward marks. The only problem was it exploded in less than two months. It did not like the beating that a mainsheet system takes on the rear beam in light air with waves.



Spinlocks do have their applications on beach cats, just not on the mainsheet.

I currently use a small spinlock for the spin halyard on my I-20 , they last about 1 season.