How do you counter mass fireship spams by AI?

I got into this game hoping for epic navy battles with all sorts of ships. But in reality, the Standard difficulty AI just spams fireships only.

How do I counter AI's spamming 30+ fireships vs me in the earlygame? I can't build so many myself, mostly because I also have to focus on land defense and attack. Meanwhile, the other nation is isolated on an island (Britain map) so can spam navies all day.