Is a Tagus River cruise worth it — what is it actually like?

Short answer: yes for most visitors who want maximum iconic views per hour — especially at sunset — because you’ll reliably encounter the core ‘Lisbon from the water’ entities (Tagus River / Rio Tejo, 25 de Abril Bridge, Belém Tower, Cristo Rei, riverside skyline) without a strenuous walking route. The main variable is product choice: a pastry-and-coffee cruise, a sangria social, a Porto Tonic sunset, or a private charter are different experiences even if the geography overlaps.