How many Unique Frigates/ships are there to add to your fleet?

I have the ones shown in the photos:

Top left: The Normandy Top right: Pirate Frigate Bottom left: Living Frigate Bottom right: Cursed/Doomed Frigate

Are there any others and where can I locate them? Any help would be appreciated. Thank you!

I have the ones shown in the photos:

Top left: The Normandy Top right: Pirate Frigate Bottom left: Living Frigate Bottom right: Cursed/Doomed Frigate

Are there any others and where can I locate them? Any help would be appreciated. Thank you!