Okay, I want to make a tower / turret that shoots only at the sea. Obvious I give it navaltargeting=all with primary, and landtageting=never. But the real question is wether it would look best placed in the water like the naval yard is or placed on the shore, with a wide range.
If it is only going to target naval targets, then I think it should be placed in the water. To allow all combat naval vessels to fire on it and to save space on land. Laotze put a tower in the water in his mod, I think.