I was playing as the Siam in a war against the English on Warlord difficulty. In the battle (land and sea) I had destroyers, battleships, modern armour, and mechanized infantry. England had Caravels, crossbowman and longbowman. This was an archipelago map. My strategy was to smash the cities with naval bombardment and then take them quickly with tanks. All of my embarked units were escorted by multiple warships. So in the entire sea battle I encountered 1 Caravel as opposition. I range attacked it with 1 battleship and 1 destroyer. I was astounded that this only took the caravel down to half hit points! So I took my last battleship in the area and attacked it directly. This brought the Caravel down to about 10% hit points!! The next round the caravel proceeded to sink an embarked modern armour... All I can say is this is Civ1 warrior killing battleships all over again 
How in the hell does it make any sense that a caravel could survive 3 attacks from modern warships? Secondly does it even make any sense that a caravel could sink a modern 50,000 ton towering steel transport? The modern transport would just run it over like so much flotsam. A caravel should not even survive 2 frigates let alone a modern navy.
Also the embarked units need to be reworked. It makes sense that an unguarded transport is completely vulnerable to warship from its own era but its a bit much to imagine a modern transport having any vulnerability to a caravel.
I think embarked units need to have a low defense points that go up with each passing era or each key naval technology. There would be just enough hit points to reasonably defend against hopelessly obsolete war ships, but still few enough that a contemporary warship would kill it like a hot knife through butter.

How in the hell does it make any sense that a caravel could survive 3 attacks from modern warships? Secondly does it even make any sense that a caravel could sink a modern 50,000 ton towering steel transport? The modern transport would just run it over like so much flotsam. A caravel should not even survive 2 frigates let alone a modern navy.
Also the embarked units need to be reworked. It makes sense that an unguarded transport is completely vulnerable to warship from its own era but its a bit much to imagine a modern transport having any vulnerability to a caravel.
I think embarked units need to have a low defense points that go up with each passing era or each key naval technology. There would be just enough hit points to reasonably defend against hopelessly obsolete war ships, but still few enough that a contemporary warship would kill it like a hot knife through butter.