Water, water, everywhere.....

[Anomalocaris]

Citation needed.

Oceans were here before continents.

http://www.sciencedaily.com/releases/200...075438.htm

Many geologists agree with this scenario, Moores said. What is controversial is how quickly the Earth changed from a planet covered in water with a few mountainous islands to one with large continental landmasses. According to Moores' theory, the continents emerged quite suddenly, over about 200 million years, at the same time that the supercontinent Rodinia was forming

We've also had ice ages which nearly covered the earth in water ice.

That is an odd statement, since geologists think plate tectonics had already cycled through several ~500 million year long supercontinent cycles, where large continentals coalesce and the breakup, going back 3 billion years, long before the supercontinent of Rodinia formed. It seems an unusually high proportion of core of modern continents were formed between 3.5-2.5 billion years ago.