AI not upgrading ships?

[Jubala]

Is it just me or does the AI seem poor at upgrading ships? Land units seems to get upgraded just fine, but I frequently see old wooden ships floating around when I know the AI can build better destroyers or better. See attached screenshot for an example.

[Peets]

ran out of money?
Or they feel it's not need yet?

EDIT: In my last game, the stronger ones did upgrade their fleet units but the weaker ones didn't. But they also didn't upgrade their units that well.

[Mace]

Maybe that AI civ did not have oil. I don't think mech inf requires oil, but Destroyers sure do. You can upgrade a Frigate or Galleon unless ya got oil.

[Kekkonen]

Lack of oil is a pretty good guess, since it also explains the other conspicuous thing about the pic -- Isabella has mech. and SAM infantry, but still relies on cavalry as the mobile offensive unit.

[Jubala]

Lack of oil could be the reason this time, but I have also seen the AI using galleys when it has both galleons and frigates. This is the second war Isabella has started with me in this game. In the first war I sank her entire wooden navy with my destroyers so launching a second war against me without having begged, stolen or borrowed oil to get some decent ships when we are on two different continents seems like a poor strategic decision on Isabellas part.

[Edit: Spelling]

[Proteus_MST]

Maybe she hates you so much that it doesn´t matter to her if she is able to win the war
Or she hopes that the 3 Frigates might be enough to protect her galleons at least until they are able to deliver their units (and hopes that your cities don´t have too much defenses).