Rhodes Town: Submarine Cruise with Underwater Views

The best part of this Rhodes boat trip comes when the vessel pauses offshore and a diver appears outside the large underwater windows, scattering food among hundreds of fish. You stay inside the air-conditioned underwater cabin, 2.5 meters below the surface, while the boat itself remains above water.

I like two things here: the excellent value at $23, and the useful mix of harbor views, local sights, and marine life. You get a fresh view of Mandraki Harbor, the Old Town walls, Elli Beach, and the site linked with the Colossus of Rhodes without giving up half a day.

The main caution is space. The lower cabin can feel warm or crowded when everyone heads downstairs, and several people have found the commentary difficult to hear. Water clarity and window cleanliness can also affect the underwater view.

Key points to know before boarding

• The diver feeding the fish is the main event: Have your camera ready when the fish gather outside the windows.
• The boat never fully submerges: Only the viewing hull sits below the surface, making this easier for people who dislike traditional boat trips or underwater activities.
• The route covers Rhodes highlights: You pass Mandraki Harbor, Elli Beach, the Tourist Harbor, the Old Town walls, and the area associated with the Colossus.
• The trip lasts 45 minutes: That is long enough to feel worthwhile but short enough to fit around a day exploring Rhodes Town.
• The 6:30 p.m. departure skips the fish-feeding show: Choose another time if the underwater presentation is your priority.
• It works especially well for families: Children get a clear, active focal point, while adults get harbor views and a little local history.

What the Poseidon Submarine actually is

Despite the name, this is not a submarine cruise in the naval sense. The Poseidon is a boat with an underwater viewing section. The main vessel stays at sea level, while the hull and observation cabin extend about 2.5 meters below the surface.

That distinction matters. You can sit in an air-conditioned cabin and look through large windows at the seabed and passing fish, then return to the open deck for sea air and views of Rhodes. You are not sealed inside a vessel traveling far below the water.

The underwater room is the reason to book, but the boat ride itself is part of the appeal. The route gives you a different angle on Rhodes Town, especially the harbor entrances, fortifications, beaches, and waterfront landmarks that can look familiar from land but quite different from the water.

There is a bar onboard, although drinks are not included. An audio guide is provided in English and German, and the activity also lists a live English-speaking guide. In practice, the commentary may be hard to catch when music is playing or when the boat is busy, so treat the spoken information as a useful extra rather than the main reason to go.

Starting at Mandraki Harbor

The meeting point is at Mandraki Port, opposite the Bank of Greece building, at Pl. Eleftherias 85100. This is a convenient spot in central Rhodes Town, close to the harbor sights and within easy reach of the Old Town.

Allow a little time to find the Poseidon Submarine and get settled. The boat has been easy to locate for people using the ticket map, but the port has plenty of activity, so arriving early is sensible. One useful detail is that early arrivals may be allowed to wait onboard rather than standing around the dock.

The exact boarding routine can vary with the departure, but the experience is designed as a straightforward harbor excursion. There is no long transfer from a hotel or bus ride into the countryside. You meet at the waterfront and begin seeing Rhodes almost at once.

If you use a wheelchair, the activity is listed as wheelchair accessible. Still, because boats can have ramps, steps, and separate deck levels, I would confirm the boarding arrangement when booking if you need detailed assistance.

Ten minutes around Mandraki Harbor

The first section takes you around Mandraki Harbor. This is one of the most recognizable parts of Rhodes, and seeing it from the water helps you understand the shape of the city.

The harbor is linked with the story of the Colossus of Rhodes, the enormous ancient statue traditionally said to have stood near the entrance. The statue itself is long gone, and the exact historic location remains debated, but the harbor setting gives the old story a useful sense of place.

You also get views toward the harbor structures, waterfront buildings, and the town behind them. The route is not a full archaeological tour, so you should not expect a long lecture on ancient Rhodes. Instead, it provides a short orientation while the boat moves at an easy pace.

This part is especially helpful early in a Rhodes visit. From the deck, you can begin to place Mandraki Harbor, the Old Town, and the nearby coastline in relation to one another. If you have already walked the harbor, the boat gives you a new angle rather than repeating exactly the same view.

Passing the Palace and the Old Town walls

The cruise continues past the area of the Palace of the Grand Master of the Knights of Rhodes and along the seaward side of the Old Town. This is one of the strongest visual sections of the trip.

From the water, the medieval fortifications appear as a broad defensive edge rather than a series of streets and gateways. You see the walls from a distance, which helps explain why Rhodes was such a powerful fortified port. The palace itself is part of the larger Old Town setting, and the audio information adds a little context as you pass.

The route also includes the Old Town, the Tourist Harbor, and views toward Elli Beach. These stops are not shore visits. You remain on the boat, so think of them as moving viewpoints rather than a guided tour with time to walk around.

That limitation is worth stating clearly. If your main goal is detailed history, spend your sightseeing time inside the Old Town with a walking tour or museum visit. If you want a relaxed way to see the walls and waterfront without more walking, this cruise earns its place.

The 20-minute underwater viewing session

The final section is where the trip changes from harbor sightseeing to a simple marine-life show. The boat pauses in an area outside the port, and you can go below to the underwater observatory.

The cabin has large windows intended to provide a broad view of the water around you. The seabed, rocks, sea grass, and fish are the main sights. The clearest and most active moment comes when the diver enters the water and feeds the fish directly in front of the windows.

This is not an aquarium with many carefully separated species. You may see a concentrated group of local fish gathering in one area, and the marine life can be less varied than children expect. There are no promises of sharks, whales, or a long list of rare creatures. The appeal is the close view of ordinary Aegean sea life in its own setting.

Water conditions make a difference. On a clear day, the view can be memorable, with fish moving over the seabed and the diver working close to the windows. At other times, cloudy water or dirty glass can soften the effect. The windows have been described as clean on some departures, but not always spotless, so it is wise to keep expectations realistic.

The feeding show gives the underwater portion a clear focus. Without it, you might spend only a few minutes looking at fish and rocks. With the diver present, children have something to watch, and adults can take photographs or short videos as the fish gather.

Some departures have also included photographs or underwater video of people onboard, shared through the operator’s Facebook page. That is a pleasant extra when offered, but it should not be treated as a guaranteed inclusion.

Choosing between the lower cabin and the open deck

You do not have to stay below for the whole trip. The open deck lets you enjoy the breeze and take wider photographs of Rhodes, while the lower cabin provides the underwater view.

I would switch between the two rather than staying in one place. Use the deck during the harbor portion, when the Old Town walls and waterfront are the main attraction. Move downstairs when the fish-feeding presentation begins.

The lower level can become crowded, especially when everyone wants a clear view at once. It may also feel warm and sticky despite the air conditioning, and some people have found it uncomfortable after five or ten minutes. Seating can be an issue if others leave bags or spread across several seats, though the crew has helped reorganize the cabin when needed.

For the best chance of a seat, board promptly and head below when the underwater portion begins. If you are traveling with a young child, sit where the window view is clear, then take turns stepping onto the deck if the cabin feels too warm.

How good is the commentary?

The trip includes an audio guide in English and German, with English listed as the live tour language. The information covers sights around Rhodes, including local history connected with the harbor, the knights, the walls, and the city’s waterfront.

The content is useful for a short orientation, but sound quality has not been perfect on every departure. Music can overpower the recording, and the commentary may be difficult to hear from some parts of the boat. If learning the history is important to you, listen closely near the speaker and use the trip as an introduction rather than your only history lesson.

The underwater section could also benefit from more explanation about the fish. You see plenty of activity, but the presentation is more visual than scientific. I would have liked clear identification of the species and a little information about the local marine setting.

That said, the short format works in its favor. You are not sitting through a long lecture when the main purpose is to see Rhodes from the water and watch the fish.

Price, timing, and overall value

At $23 per person, this is one of the easier Rhodes activities to recommend on price alone. A 45-minute boat trip with harbor views, an underwater observatory, a diver feeding fish, and access to a deck gives you several kinds of entertainment in one compact outing.

The value is strongest if you want a short activity between walking tours, meals, or a visit to the Old Town. It also works well on a day when you want something restful but still want to see more of Rhodes.

The value is less certain if you expect a full marine-life expedition. You are not traveling far offshore, and the underwater habitat may center on one group of fish. This is a harbor cruise with an underwater viewing feature, not a substitute for snorkeling, scuba trips, or a dedicated wildlife excursion.

The 45-minute length is a real advantage for families. A child who gets restless on long boat rides has a better chance of enjoying this one from start to finish. Adults also avoid sacrificing an entire afternoon.

Book a departure before 6:30 p.m. if the diver show matters to you. The 6:30 p.m. cruise does not include the diving show, so it is better suited to harbor views, the sea breeze, and sunset timing if that is what you want.

The activity offers free cancellation up to 24 hours in advance and a reserve-now, pay-later option. Those policies give you some flexibility if your Rhodes plans depend on weather or changing port schedules.

Who will enjoy this Rhodes cruise most?

I would recommend it first to families with children, especially children who enjoy fish, boats, or anything that feels a little different from a standard sightseeing walk. The diver creates a clear moment of excitement, and the short trip leaves plenty of time for the Old Town afterward.

It also suits couples and solo visitors who want an easy harbor view without committing to a long excursion. You can sit on deck, listen to the commentary when audible, and take in Rhodes from a quieter angle.

It is a good choice for anyone with limited time in Rhodes Town. Since the boat leaves from central Mandraki Harbor, you can combine it with the Old Town, harbor promenade, Elli Beach, or a meal nearby.

I would be more cautious if you need a quiet, spacious boat or expect polished museum-quality interpretation. Crowding below, uneven commentary, and occasional cloudy water are the main weaknesses. The experience is cheerful and simple, not luxurious or highly technical.

Should you book the Poseidon Submarine?

Book it if you want a low-cost, family-friendly 45 minutes that combines Rhodes views with a close look at fish. The diver feeding the fish is the reason this modest boat trip feels more special than a basic harbor cruise.

Skip it if you are looking for a serious marine-life tour, a long open-water cruise, or detailed historical guiding. For most visitors, though, the price, central location, short duration, and mix of deck and underwater views make it a sensible addition to a Rhodes Town day.

Choose a daytime departure before 6:30 p.m., arrive ready to claim a good lower-deck position, and keep your camera handy. Just remember that clear water and a quiet cabin are not guaranteed. With those expectations, this is an easy, good-value way to see Rhodes from a different side.

FAQ

Where does the Rhodes Submarine Cruise depart?

The boat departs from Mandraki Port at Pl. Eleftherias 85100. The Poseidon Submarine meeting point is opposite the Bank of Greece building.

How long does the cruise last?

The cruise lasts 45 minutes, including the harbor sightseeing and underwater marine-life viewing.

Does the boat go fully underwater?

No. The vessel remains above sea level. Its underwater observation hull sits about 2.5 meters below the surface.

Is the diver feeding show included on every departure?

No. The 6:30 p.m. cruise does not include the diving show. Choose an earlier departure if watching the diver feed the fish is important to you.

What languages are available?

The activity includes an audio guide in English and German, and an English-speaking live guide is listed.

Is the boat wheelchair accessible?

Yes, the activity is listed as wheelchair accessible. If you need specific boarding assistance, confirm the arrangements before departure.