In Archipelago, say you have already played all your action discs, but for an arbitrary reason you did not use your ports or markets. Does this means you cannot use them anymore in this action phase?
You cannot use the ports or markets if you have no action disks left to play.
The easy way to think about this is:
On your turn:
So if you don't have any action markers, you won't be able to use a port/market.
Ok, found the answer to that in the manual, page 8.
So, yes, you can still use a market or port, if you're able to.
It seems I might've misunderstood the rules. The correct answer, I think, is you can't!
In page 8, you read:
The concept of round is important here. A player has a round "until all players have used up their action disks or cannot play anything".
In page 12, you read:
This means that you can only use market or ports once per round if you have a round. Therefore, you can't use them after your action disks have finished.
Likewise, this is extensible to evolution cards (page 14):