Sea Route and Ocean tile

[cheerful]

Can sea route contain ocean tiles? I have 2 island separated by a distance of 6 with a band of ocean tiles in the middle.

Thanks!

[Raleigh]

Someone explained this too me but now I being to forget

In the beginning, when you have galleys, you only need writing and can trade over coasts. Then, when you discover astronomy you can trade over seas and navigation means oceans.

I dk if this is true, but it has explained a lot of my own confusion. Hope it helps!