There are 2 types of tsunamis.
Your regular, every day type tsunami and the Super Sized variety.
If a regular tsunami is headed your way, gather up all your belongings (and your children if they've been good) and proceed in a calm and organized fashion out of the tsunami zone... Out being the key word here.
Once there you may pour yourself a cocktail and watch all the idiots walking around in the tsunami zone eager to see a tsunami "up close" (Darwin assures me there will be many). After they have all been devoured, feel free to help yourself to anything that belonged to them... after all, they won't be needing it now. And in postapocalyptic times that Gucci handbag you found buried in their closet will be like having gold in your pocket... trust me.
So remember: Out good. In bad.
If, instead, the giant Super Sized tsunami is set to invade your coastline, immediately pack up anything breathing (grandpa, too) and head for the Rockies.
Once there you should immediately invest in property, as this will now become beachfront and be highly desirable.
Until the next tsunami, that is.