If you wait until oceans were going up 10m in a week, you're going to have a lot of people panicking and fighting over boats.
In order to avoid panic, you have to prepare well ahead of time. Airlines tell you what to do in an emergency when the flight starts, they don't wait until the plane hits the water.
In order to avoid panic, you have to prepare well ahead of time. Airlines tell you what to do in an emergency when the flight starts, they don't wait until the plane hits the water.