I understand and accept your choice, but I can also regret it... Well not really because you use your time making other useful units.Because I don't wanna.
And I chose not to because then I'd have even more requests if I expand into other genres.
I have more models than I have time. So I chose not to pursue every cource at once.
We have a few fine sail ships. the Ship of the Line, an heavy Frigate..
Yes we have a great selection starting from the Age of Discovery period, and we also have a nice lineup of oriental ships, but we're lacking middle-eastern / indian (wont bother to mention african) for both ancient and medieval periods, and perhaps a few more ancient ships for the western civs.
There are a few great mid-east/african/arabian Units floating around CFC that I'm using in my mod:
Galleass (Used by mediterannean civs in the 14th to 16th centuries, especially north African Pirates, and the Turks):
http://forums.civfanatics.com/showthread.php?t=79551&highlight=galley
Dhow (Used extensively in the Arab world, especially in the Red Sea, Persian Sea, and East Africa):
http://forums.civfanatics.com/showthread.php?t=41777&highlight=dhow
These are both Early to Late Medieval period though.
Not too sure, but I don't think that you are going to find any historically accurate Middle-Eastern or African 16th to 18th century sailing vessels. I don't believe that those cultures took a great interest in the age of sail. Your only exceptions would most likely be the Arab Dhow or the Gallivat, but the Galere also looks like it's design was influenced by the design of the Dhow. I found a link to a good website for sailing vessels to the time period here. Hope this helps.