Hi Gollum and Caravel, interesting discussion about ships and sea regions!

I've reading your posts about this matter and I would like to see how this will affect gameplay. But I also have an idea: "make small independent sea zones" which don't border with their current sea neighbours, only with their land neighbours. Then you could deploy ships in this small sea zones but preventing silly invasions like you have noted and keeping the possibility of "historical" invasions (for instance Naples-Epiros, Sicily-Tunis, Morocco-Andalus...). I also think the movement of agents would result more "natural".