For some reason, in Civ3, submarines are very underpowered. When attacking an aircraft carrier, they have a high (over fifty percent) chance of losing. So, I prepose that in Civ4, Submarines primarily attack enemies with something like the Civ3 bombard. It would have a quite high rate of success though, with that rate increasing as the submarine (and sonar and torpedo) get upgraded to more modern technology. Submarines seem to be being explored fairly well in Civ4 with stealth attack, but they are still underpowered, IMO. I would personally mod them to have a good bombard strength, but
1. They would be able to bombard land, and I only want the most modern ones to be able to do that
2. You can't have "stealth bombard."
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In history, torpedo bombers played a significant role. However, they are impossible to all to Civ3, because they could bombard land. But, it would be interesting to add them in Civ4.
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IMO, Civ4 should have a "torpedo" model. Both submarines, and torpedo bombers would work off of this model. They would be more deadly, and perhaps more accurate than regular bombs, but could only be launched at sea. This could also open up the possibility for PT (patrol torpedo) boats that could fire torpedoes.
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Then, there could also be underwater mines. You ships and subs could avoid them, but enemies, who don't know where they are can't. Perhaps minesweeper ships could remove them. Modern ships with modern sonar could see them, but would have to go to another square to avoid them. Perhaps mines could be produced in coastal cities, carried by boat to the destination square, and released. They would then be automatically fortitified until either hit, or X turns pass, and they time out, and disappear. When a ship hits them it will work off of the "mine model," explode, and do some damage. The damage could either sink, or badly damage the ship.
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Mines and torpedos could also turn out to be dud when they explode.
.l
