I think trying to take a trailered boat through the debris after a major quake would be a joke, and not a very funny one. I would bet that getting a 4WD fifty miles south would be a real trick.

And having a boat on water soon after a quake... uh... no, thanks. Even if it didn't cause a tsunami, the probable multiple aftershocks would make rough going. Not to mention all the debris in the water.