Mine is about 15' long but that is too much. I tied a figure eight knot at the proper length so that I can slip it under the hook of my harness. This should allow me to hold the mast up a little while I get my bag ready to help me right it. This is all theoretical since I haven't capsized yet. I'm still waiting to build the nerve (and warmer water). I built the bag last winter and never really set it up on the boat, so now I find myself again waiting for warmer water to practice. I still carry it in case of an emergency but I still don't push the boat as much because I haven't proven it works. I'm pretty sure my mast is not perfectly sealed.

-Rob V.
Nacra 5.2
Panama City