the concept of unsinkable yachts
I doubt all seaworthy sailboats can survive hitting a submerged object. There may be some that can, and maybe you''ve been on a few of them, but most sailboats are not built to withstand catastrophic collisions.
Etap has an interesting design. Perhaps their improved safety will become more popular as more families go cruising. (Keep in mind, automotive safety only became popular after the sixties, as more women started driving and long distant family vacations became easier as a result of new interstate highways.)
~ Happy trails and sails to you ~ _/) ~