At some photos (4 - 7) it even looks like a lake to me as the water is so calm
The ocean in our backyard is deep in a cove, and the water is always calm, as it slowly rises and sinks. If we have big storms we finally can see some waves there, but it is extremely rare.
This is what it looks like at low tide (photo from 2014):
And in the winter: (video I took in 2015)