As a big fan of Civ 6 compared to 5; one area in which I think the game went backwards was in navy's. Civilization has always struggled to make them relevant; but I think 5 had come up some improvements with the ability to blockade cities from trade (edit: it was 4 that added blockades). Obviously not having to build cities on the coast played into that as well; though I do hope districts stay in Civ 7; so I don't think that will change. But... aside from a Pangaea map; navy's ought to be central to winning the game. I think re-separating out the trader into a land only version and a sea only version is crucial; as ultimately it is the superiority of sea trade that makes navy's so important in our history and today. I would have something like land caravans cost half of what trade ships do; but deliver only a third of what the ships do. I would bring back the blockade function in some form; and have it be possible to effect trade items from Civ's overseas as well as the trade routes themselves. To help make defending trade ships more practical, I'd have a "merchant navy" function where a military ship could be linked with a trade ship as it moves it's one tile per turn (the military ship would pause outside of waters within the boundaries of a foreign Civ and wait for the trader to return outside of those borders, before moving with it again). I would make embarked land units even weaker in water so that any sea invasion without a supporting navy is easily repealed by a moderate navy. I would have an early barbarian ship that was weaker than the Galley; but that made sure that players had to build naval ships to defend their sea trade routes. I would make healing ships easier to do, as they can be a risky investment early in the game as they can only heal inside your borders. I would extend that to be able to happen in any civ's borders that you have open. I think land caravans should still be what build roads; which will keep them relevant even once people can build trade ships. Thoughts?