Rotterdam harbor tour

Any walking city tour should cover that. There are several offered, if you Google. The TI also includes walking tours. Rotterdam is a fascinating city. Enjoy!

We did this tour a few years ago and really enjoyed it: https://www.spido.nl/en/cruises/rotterdam-highlights-harbour-tour

There are no walking tours of the harbor of Rotterdam, that would be far too dangerous. Besides that, the harbor is huge and located quite far from the city center.
There is only one real operator of harbor tours, the one already mentioned above; Spido.
Another, but rather different option, is the Pancake boat. Unlimited pancakes while you tour the harbor https://rotterdam.pannenkoekenboot.nl/en/

You can also go to Portlantis, a kind of a visitor center in the Maasvakte, the closest part of the Rotterdam harbour to the sea. It’s also where the world’s largest bulk carriers, container ships and oiltankers dock. If you like you can join a tour there.

https://www.portofrotterdam.com/en/portlantis/to-do

It takes quite a lot of time to get there with public transport from Rotterdam city center. I don’t speak of experience, but think can be worthwhile if you like this kind of things.

I thought the poster was asking about the charming old historical harbor in Rotterdam. I guess we need more info.

I was actually looking for boat tours of the harbor. I went ahead an booked the Rotterdam Highlights & Harbour Tour with Spido.

Rick's Rotterdam walking tour (in the guidebook) takes you through the "old harbor" area. Definitely not focused on the harbor, but you get there towards the end of the walk. It's a relatively small area, but one you could spend some extra time walking around during the guided walk. Leuvehaven had some interesting boats to look at (and a museum), and was pretty neat in general. The museum even has an inexpensive harbor tour ( https://maritiemmuseum.nl/en/activity/round-the-maritime-district ) which looks fun (wish we knew about that earlier).

The OP is looking to take a tour of the harbor of Rotterdam; the enormous harbor where the huge container ships and oil tankers dock. Not the small historical harbor near the city center.

The Port of Rotterdam is the largest and busiest port on the European continent. It’s very impressive to tour the port on a vessel like Spido. You’ll feel like a dwarf when you sail past these huge freight shops stacked with containers.

The port of Rotterdam is also home to the off-shore industry. Much is located at the western part of the Waalhaven. With a bit of luck you can spot semi-submersible crane vessels for lifting of oil and gas production platforms. Jackup rigs, pipe lay systems, so heavy things like that.

Just a few companies there:
https://www.huismanequipment.com/en/
https://www.nov.com/products-and-services/brands/gustomsc
https://www.mammoet.com/

Waalhaven is also the area for inland and short sea shipping. Petrochemical industrie is located more west in the Botlek and in the Europort part of the harbour. The huge bulk and container ships dock mainly at Maasvlakte I and II, that part of the harbor closest to the sea, but 40 km from Rotterdam city.

Depending your interest be sure the tour includes the places you want to see.

I did a harbour tour with River Cruise Rotterdam, right by the Euromast, just a few days ago and enjoyed it. It takes you out through the massive harbour complex to see the barges, containers, loading and unloading of goods and it was interesting to see the scale of the operations…largest port in Europe.
They then return to the city and continue past the starting point so you see more of the city and the architecture from the water. We liked both segments.
I would recommend it!