We visited the museum during a trip to Rotterdam in November 2014. The museum building is on the northern end of the Leuvehaven. The Leuvehaven had many museum ships, tjalks, barges, ferries and large cranes.
In the museum building itself the themes were history of Rotterdam harbour, trade and navigation and the development of the Maasvlakte as industrial area. The part on history before 1900 is kept somewhat short in the museum.
For more information see the website of the Maritiem Museum Rotterdam .
Here are some photos of the pen drawing 'De Eendracht en andere schepen onder zeil of ten anker' by Willem van de Velde the Elder, made in 1668. The Dutch inscription says: "As you can see, none of his contemporaries had the quality of the master, neither in the details, nor in sophistication and accuracy. Each detail of the 'Eendracht' is correct, every nail in the ship's hull, each thread in the sail."
Most probably the only ship model conserved from the middle ages is the Mataró-Model, built around A.D. 1425. The model was used during reconstruction of Columbus' ship Santa Maria. It supplemented the literature sources by its three-dimensionality. Here are some photos of the model in the museum. There is an article in Wikipedia about the Mataró-Model (in German).
The harbour of Rotterdam has been for a long time the freight transfer site from seagoing ships to inland waterways. One of the typical barges, the Trio of 1901, is displayed as model. A similar original ship can be visited in the museum harbour.
If you click on a photo you will get that photo in high resolution.