Just for the sake of argument, they are being sent to deep water so that any surge from an ocean impact is just a swell and not a tidal wave like it would be in shallow water.
That's what I'd do with the fleet, if it were my call. Still, I am far from convinced with this meteorite-strike stuff. All that we have is one highly dubious source, and a lot of material from sites that say this kind of thing all the time, anyway.
When there is some solid evidence of something seriously amiss, I'll start being concerned. I am close enough to the Atlantic that it'd end up in my living room from an ocean strike. But when you've got big, nasty cardiac problems, giant seismic waves aren't the first of your personal safety worries.
I'm going when God says it's time to go. Doesn't matter to me whether it's my ticker quitting in the middle of the night, or with me running down the parking lot, surfboard over my head toward a roaring, six hundred foot wall of shockwave driven water.