Here are the basic Hocklyn designations for ships, from smallest to largest:

- Attack Corvette
< Yachts {Non-military}
- Frigate
- Destroyer
< Cruise Ships {Non-military}
- Light Cruiser
< Cargo ships {Non-military}
- Cruiser
< Heavy Freighter ships {Non-military}
- Dreadnought
- Carrier
- Superheavy Dreadnought

Unlikely I'll have a Superheavy any time soon. Looking for a good Carrier pic, though.