In Civ 5, once you had the tech to enter water, all units that entered your own territory could do it.
I have builders in Civ 6 that can enter water, but my scouts can't, even after entering my own territory. Why is this?
What do I have to do to enable my scouts to enter water?
Best Answer
This is answered by the in-game civilopedia for Embarking Units .
And in text (for search engines):
Note that in civilization VI, you do not have to visit friendly territory anymore to gain this ability.