What types of ships are there?
Not a complete list, but this will give you some idea of the diversity of Merchant ships.
Dry cargo ships
The Largest is MS Vale Brasil that can carry 402,347 DWT has a length of 362m and operates with a crew of 33
The Largest is M
The Largest is MV Ocean Drover ex MV Becrux that can carry carry 75,000 sheep or 18,000 cattle has a length of 180m and operates with a crew of 45
Refrigerated cargo ships
Salica Frigo that can carry 7748DWT has a length of 132.9m
The Largest is MV T
Liquid cargo ships
Car & Passenger Ferry
MS Allure of the Seas can carry 6,296 passengers is 362 m in length and has 2,384 officers and crew
Queen Mary 2 can carry 2,620 passengers is 345 min length, and has 1,253 officers and crew
Luxury & cruising yachts
Floating dry docks