That's odd, for comparable size I would look at modern life boat design - they're designed for rescue from land to sea, or for launch from a foundering vessel, very ship shape and all that. Fully enclosed, engines for maneuvering, can be supplied and carry a multitude of provisions. Collisions with tsunami debris I can't assess, but I'm not certain that concrete construction can do much better than a steel hull in such conditions. Our floating bridges across Lake Washington are concrete construction and one of the engineering concerns is a moderate sized vessel colliding with them.
If I were really in the market for a lifeboat for TEOTWAWKI I would look to a surplus lifeboats from a largish passenger vessel, or maybe just contact the builder of such craft - either way it seems like spending an inordinate amount of money for the survival of a very few people. Building structures near populated area of the PNW shoreline is definitely being considered as an escape route in the event of tsunami from a CSZ earthquake and following tsunami.