Too much force in the tsunami wave/s even for that maneuver. I've done the same maneuver in big surf, but if you are submerged for more than a minute or so and the waves keep rolling over you with no stop you will not make it to the surface for air. It would be like being in a huge, chaotic, diabolical washing machine.
You may be correct but if faced with such situation as those people out on the seabed, I'll fill my lungs with air and flatten out on the bottom and try to ride out the initial front wall surge.