Sid Meiers's Pirates was good, as was Pirates 'Gold'. But i thought those were all DOS versions, not Mac?
Imho the best of those older games was 'Sea legends' though, it kind of revolutionised this genre wih its Voxel engine while still running on DOS, and had a real plot and story.. though you did not need to follow it.
You start your career as a young navy captain on an english frigate, being deployed to the caribbean sea. However there is a betrayal and a trap, and you will be sunk by an overwhelming spanish fleet. This is how it was supposed to work to let the story unfold... i would not accept that though, reloaded some thirty times and finally managed to get through with my ship being shot up to 4 percent hull integrity, but making it.
You can equip your ship(s), trade with them, throw things overboard when you get stuck on a sand bank.. you learn a bit about sailing and the advantages of schooner type ships.. one of the best PC games i ever played.
You can read about and download it (and others) here:
http://www.old-games.com/download/5542/sea-legends
Also a hint how to run those older games on new PCs..