Minicrociera Flegrea: Glass-Bottom Boat to the Sunken City of Baia
Sail the volcanic coast of Campania, dive into ancient Roman waters, and lunch aboard as the Phlegraean shoreline drifts by.
This Phlegraean Fields boat tour takes you across one of Italy's most geologically and historically dramatic coastlines, from the submerged Roman city of Baia to the headland of Capo Miseno, aboard the glass-bottom vessel Iris. The six-hour journey combines underwater sightseeing, two swimming stops, and a full seafood lunch served on board. Difficulty is rated easy, making it accessible to a wide range of travellers.
The boat departs from the port of Baia and heads first toward the Sunken City of Baia, a UNESCO-protected archaeological site where Roman villas, mosaic floors, and marble statues lie just beneath the surface. The glass bottom of the Iris allows passengers to observe these remains without snorkelling or diving, offering a rare window into an ancient world claimed by bradyseismic activity over centuries.
From Baia, the route follows the Phlegraean coastline past the volcanic cone of Monte Nuovo — formed in a single eruption in 1538 — and the imposing Aragonese Castle before reaching Capo Miseno, the dramatic promontory that once served as the base of the Roman imperial fleet. Two swimming stops allow guests to enter the sea directly from the boat, while the crew serves lunch in stages between the stops.
The lunch menu draws on local Phlegraean ingredients: buffalo mozzarella caprese with Phlegraean tomatoes, freselle with fresh tomatoes and tuna, peppered mussels, seasonal fresh fruit tagliata, and a soft drink. The combination of cultural discovery, swimming, and casual dining on the water makes this a well-rounded half-day outing along a coastline that rewards slow exploration.
Tour Highlights
View submerged Roman mosaics and statues through the glass bottom of the vessel Iris without entering the water.
Sail past the Aragonese Castle of Baia, a landmark of Angevin and Spanish rule overlooking the Phlegraean Gulf.
Observe Monte Nuovo, the youngest volcano in Europe, rising directly from the shoreline of the Phlegraean Fields.
Reach Capo Miseno, the ancient Roman naval base and one of the most scenic headlands of the Gulf of Naples.
Enjoy two swimming stops directly from the boat along the Phlegraean coast in clear, calm waters.
Savour a locally sourced lunch served in two stages on board, featuring Phlegraean tomatoes, buffalo mozzarella, and fresh mussels.
All areas of the boat are wheelchair accessible, offering an inclusive experience on the water for guests with reduced mobility.
Itinerary
The tour begins at the port of Baia in Bacoli, where passengers board the glass-bottom vessel Iris. The crew provides a brief safety and orientation briefing before casting off along the Phlegraean Gulf.
The Iris positions itself over the submerged ruins of ancient Baia, allowing passengers to observe Roman mosaic floors, statuary, and architectural remains through the transparent hull. This UNESCO-protected site sank gradually due to volcanic bradyseism and remains one of the most intact submerged cities in the Mediterranean.
The boat continues along the coast, passing the volcanic Monte Nuovo and the medieval Aragonese Castle. Commentary from the crew contextualises the geological and historical significance of both landmarks.
At Capo Miseno, the boat anchors for the first swimming stop. Guests may enter the sea directly from the vessel. The first part of the on-board lunch is served during this stop: caprese salad with Phlegraean tomatoes and buffalo mozzarella, freselle with tuna, and peppered mussels.
The Iris navigates back along the Phlegraean coast, offering a second swimming stop at a scenic anchorage. The remaining lunch course — seasonal fresh fruit tagliata and a soft drink — is served before the return to port.
The tour concludes with arrival back at the port of Baia in Bacoli, completing the six-hour circuit of the Phlegraean Gulf.
What Is Included
Included
- Six-hour glass-bottom boat excursion aboard Iris
- Visit to the Sunken City of Baia (viewed from boat)
- Two swimming stops from the boat
- On-board lunch: caprese with Phlegraean tomatoes and buffalo mozzarella
- Freselle with fresh tomatoes and tuna
- Peppered mussels
- Seasonal fresh fruit tagliata
- One soft drink per person
- Background music on board
Not Included
- Additional beverages beyond the included soft drink
- Personal snorkelling or diving equipment
- Travel insurance
- Transport to and from the departure port
- Gratuities for the crew
Important Information
Ready to Explore the Phlegraean Gulf?
Secure your place aboard the Iris for a six-hour voyage through volcanic coastline, submerged Roman history, and clear Campanian waters. Places on each departure are limited.
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