Wendy, Congrats on the new vessel! I don't know the Mystere, but on my Hobie there's a pin to put through the mast base when raising or lowering. It goes through below the socket for the ball, and creates a sort of lock. I would hope that any newer boat would have something like this. Another thing to consider when righting, I once flipped in a gust as I leaned over to pull on my downhall, I never did cleat it. Went for a swim first. As the boat righted, the main came unhooked, and came down. I couldn't get it back up on the water by myself, but luckily had a friend jump aboard to help. So I'm not too keen on releasing the downhall... The 4.3 looks like a great boat. Have fun!