IMHO, this is the finest of the old GDW supplements, reissued by Heliograph, for contents and organization. The artwork and maps are beautiful. I give it 10 stars.
The first half of this supplement covers the Cloud Captains, both Martian and human. The captains from earth are nicknamed “The Red Captains”. The information is more expansive than the basic facts provided in the Ubiquity Core Rules. Not only does it detail the important personages in the skies of the Red Planet, but is a reference on ships and practices. In addition to educating readers regarding the Red Captains, there is helpful information regarding becoming a Privateer, hiring a crew, and Prize Rules for dividing the spoils. In the campaign I am currently running, the Player Characters have acquired a ship and a Letter of Marque from the Governor General, so this supplement is close at hand during our sessions.
Most of the second half describes in exquisite detail the Martian city state of Karkarham, a city that has been likened to port of Tortuga, during the days that pirates roamed the Caribbean Sea on earth. Again the details are exquisite regarding the city and hangouts, denizens, culture, and encounters.
Finally there are a few pages on weapons that can be added to Sky Galleons of Mars, which are the rules for ship to ship combat. I also use Sky Galleons when needed, but I understand that Clockwork is working on an expansion covering aerial ships and I’m curious on what they will produce.
I have had little trouble adjusting stats from this book to the Ubiquity system.