The Pacific Ocean is vast!

Flying from San Francisco to the Hawaii islands seemed to take forever, partly because all you could see out of the window was sea. Miles, miles and miles of it. Google Earth proves the point:

In the picture, you can just see the Americas on the right hand edge, and Australia on the left hand; otherwise it's all water!

(By the way, you can also see the archipelago of Hawaii not quite in the middle - we are not even half way across yet!) The Pacific Ocean is big. Really big. Huge. It must be the biggest sea on the planet. What can you learn about it?