The mantas don't have stays, they have and aluminum frame holding the mast, you can capsize but it just kinda falls over and bounces around,(seen it, haven't done it) Incedentily we do have seat belt and when the wind is blowing good we were motorcycle helmets, if its REALLY blowing good(mind you at this time, My buddy and I tend the be the only two sailing,) I also wear my motorcycle jacket with the kevlar/carbon pads. Its been my experience that they are hard to capsize, if you get into trouble its usually with the steering, and if you just drop the mainsheet the boat will do a few of those nifty 360's like in the first video, when you ge tyour bearing you take off again. The big boats are a little differnet storie, their sailors really don'tpush them up enbough to "fly a hull" (wheel) they are a little too valuable, but htey are also not designed to do that, the axels are super wide. Landsailing is a little different in the absolutely no one is going to risk a collision, that would be fairly disasteous in any of these boats, so you stay well clear despite any right-of-way rules you think that other guy is breaking, In fact I think that the upwind boat has the only right of way, otherwise its everyone's responsibility to avoid.