This topic arises every now and then. And - as always (
) I want to promote my "Coastal Fortification"-idea:
- buildable at coastal tiles (adjacent to land only) anywhere on the map, but not inside other culture influence zones
- converts a 2 hex range of water tiles into your culture. (Though no culture flipping of already acclaimed enemy borders.)
- casts a ZoC of 2 hex against enemy ships. (= slows ships down like the Great Wall does on land.)
- can attack ships within 2 hex range.
(- ships may heal additional 10 HP/turn if stationed inside. This is not really necessary, as the cultural influence zone itself already allows ships to heal.)
The idea behind this:
a) helps to defend coastal cities against raids
b) helps to defend naval trade routes against raids
c) may control straits (I love especially this aspect)
d) may be used as sea outpost far away from the own empire.
--
furthermore:
e) is very close to the Great General's ability but not exactly the same.
f) is longer lasting and not so out-of-time in early eras than mine fields.
g) While canals are an interesting and maybe needed addition to the game, I don't think they fit very well to Admirals. After all, canals are mainly used for civil purposes (trading!) and should be a wonder or even a standard (but very expensive) tile improvement.

- buildable at coastal tiles (adjacent to land only) anywhere on the map, but not inside other culture influence zones
- converts a 2 hex range of water tiles into your culture. (Though no culture flipping of already acclaimed enemy borders.)
- casts a ZoC of 2 hex against enemy ships. (= slows ships down like the Great Wall does on land.)
- can attack ships within 2 hex range.
(- ships may heal additional 10 HP/turn if stationed inside. This is not really necessary, as the cultural influence zone itself already allows ships to heal.)
The idea behind this:
a) helps to defend coastal cities against raids
b) helps to defend naval trade routes against raids
c) may control straits (I love especially this aspect)
d) may be used as sea outpost far away from the own empire.
--
furthermore:
e) is very close to the Great General's ability but not exactly the same.
f) is longer lasting and not so out-of-time in early eras than mine fields.
g) While canals are an interesting and maybe needed addition to the game, I don't think they fit very well to Admirals. After all, canals are mainly used for civil purposes (trading!) and should be a wonder or even a standard (but very expensive) tile improvement.