There should be something to hold the tension but in the top of the mast, not int base. Either a hook fo fit a ring in the halyard, on the rear side of the mast, or something to fit the tip of the wire (nicopress oval) in, in the front of the mast. You still need to attach the halyard somewhere near the base, but just to keep it there, not to hold the sail. I made my mast rigging and prefered to attach the halyard near the mast base, but it must be a wire to avoid stretching, and you need appropriate sheeves.
About keeping the boat on the water, it's not a very good idea.