Help me plan my battle strategy, I'm new to Civ5 MP

Me and my friend are in a tense battle of Civ5 MP. Currently we are in between play sessions. I'm requesting help with my battle strategy. It is turn 184 and our peace treaty expires 188. I'm Ottoman He is England
**The victory is domination only.
This is a custom map which we are "not" allowed to paratroop/bomb across the mountain range.
The turns are simultaneous (sigh) and that makes them about speed early moves.
We are playing gods and kings.
The world follow my religion.
We are both at future tech.
He has taken 2 of my cities and i have taken 5 of his.
He has a larger military.**
I made the early mistake of only producing Battleships (because of Ottomans 'prize ships' ability)
We have 4 turns left of a peace treaty and both have decided to go for capitals for a swift kill.
Image of the mini-map viewer: http://i.imgur.com/QwXMUJk.jpg
Image of MY capital: http://i.imgur.com/AQAkIit.jpg
Image of an area around my capital: http://i.imgur.com/eeI6KST.jpg
Image of an area in his boarders, I control: http://i.imgur.com/68PAKiM.jpg?1
Image of HIS Capital: http://i.imgur.com/e3NKGcE.jpg
Image of area around HIS Capital: http://i.imgur.com/Kh1sz15.jpg
Image of an area under my control of interest: http://i.imgur.com/IwI9z2a.jpg
Image of the range of nearest city bombing range: http://i.imgur.com/HuI8sTl.jpg
My current plan is to take Coventry and bomb him from there. Not being on the coast will make it hard for him to attack there.
Please help. Ideas?

Against all those subs, any attack by sea is doomed to fail. I suspect he has higher production to looking at his population numbers compared to your own.
Bombers and take out any and all ships you see. Subs can be ignored if you dont have a fleet of your own.
I dont think you can win that one, unless he's blinded by the "straight for cap" agreement.

Yeah, properly managed dominance of the water is very snowballish. You have to get him to make a mistake with those submarines, and destroy a lot of them, so that you can try to get to more equal numbers. You can't fight on the water in a modern era without subs.
Getting him to make that mistake(s) will take creative thinking and good information.