So I have conquered most of Greece, I am just finishing off the Spartans. My next task is to take all the blue islands. But the Athenians seem to have an endless supply of triremes, so much that any invasion fleet doesn't stand a chance of unloading all its troops before it is destroyed. I have resorted to distracting the AI and sneaking in a few transports while it is occupied elsewhere. But I can't gain sea supremacy long enough to support my siege troops until the city is conquered. It's left to luck if the troops survive long enough to complete the siege. To make matters worse each little island city has a huge stack of troops in it, sometimes 10 land units are stacked up there. I have taken a few islands, but there are so many. I thought taking Athens would weaken them somewhat, but they can still support a huge navy.
Does anyone have a good strategy for sea warfare and amphibious invasions? I'm considering just pumping out triremes myself and overwhelming them with numbers. But to afford that I'll have to cut back on my land army significantly. How do you guys handle this part of the campaign?