The harbour cruises that leave from the Landungsbrücken pontoons are fine. They have commentary, they are built for visitors, and they cost visitor money. But Hamburg also runs line 62, a regular ferry on the city’s public transport network, and it covers much of the same working river for the price of a standard transit ticket.
It leaves from Landungsbrücken and heads west down the Elbe toward Finkenwerder. On the south bank you get container cranes and the dry docks of the shipyards. Behind you the Elbphilharmonie shrinks into the skyline. No one tells you what you’re looking at, which I count as a feature. The port is more convincing when you’re just another commuter watching it go past.
The move is to get off early, at Neumühlen/Övelgönne.
Övelgönne is a narrow strip of former captains’ and pilots’ houses along the north bank, with no through traffic and a footpath instead of a road. There’s a small museum harbour of old vessels, and below the path a stretch of sandy riverbank where people sit with a coffee and watch container ships slide by. The ships come close enough that their scale becomes the whole attraction. A vessel the size of an apartment block moving past a man walking his dog is the most Hamburg image I know.
Walk east along the water toward Altona and the Fischmarkt area. It’s a pleasant stretch, and you can catch the ferry again at any landing along the way if your legs give out.

November
It’s grey, it’s cold, and the upper deck is exposed. Sit outside anyway for the first ten minutes. Winter light on the Elbe suits the industrial backdrop better than summer does.
Practical notes
A day ticket on the HVV network is usually better value than single fares if you’re also using the U-Bahn or S-Bahn, but check the current zones and prices on the HVV site, since they change. Ferry frequencies can also thin out outside the main season, so look at the timetable before you plan the Övelgönne stop around a specific return sailing.
The paid cruises do go places the 62 doesn’t, including the canals of the Speicherstadt, which are reached by smaller boats. If that’s what you want, book one of those and treat it as a separate outing. For the open river, the numbered line is enough.