Rhodes Town: Submarine Cruise with Underwater Views

See Rhodes from a different angle. The Poseidon Submarine cruise gives you a short, easy look at Mandraki Harbor, the Old Town walls, and the sea life just outside the port. I like the mix of sightseeing and underwater viewing, and I like that the whole trip takes only 45 minutes. The main thing to consider is that the lower cabin can feel crowded, warm, or hard to see from when the boat is full.

I especially like the diver feeding hundreds of fish right beside the underwater windows. It turns a simple harbor cruise into a small show, and children usually get the biggest thrill. I also like the choice between sitting in the air-conditioned underwater cabin and heading onto the deck for fresh air and views of Rhodes.

This is not a serious marine research trip, nor is it a full coastal excursion. You will see a limited area of seabed, and the water can sometimes be cloudy. Still, at about $23 per person, it offers a pleasant and inexpensive break from walking the stone lanes of Rhodes Town.

Key points to know before boarding

• The underwater cabin sits 2.5 meters below the surface, while the vessel itself remains above water.
• A diver feeds the fish beside the windows, creating the most memorable part of the 45-minute trip.
• Mandraki Harbor views include the Old Town walls, Elli Beach, and the former site of the Colossus of Rhodes.
• You can move between the lower cabin and the open deck, so you are not confined below the surface.
• The 18:30 departure has no underwater feeding show, an important detail if that is your main reason for booking.
• The trip is wheelchair accessible, with an English live guide and an audio guide in English and German.

What the Poseidon Submarine actually is

The name can make this sound like a conventional submarine. It is better understood as a sightseeing boat with an underwater observatory built into its hull.

The ship stays above sea level throughout the trip. You go down into a lower viewing cabin, where large windows give you a broad view of the water and seabed at about 2.5 meters below the surface. This setup feels less enclosed than a true submarine, and you can return to the main deck whenever you want.

That arrangement works well for mixed groups. I can imagine one family member enjoying the fish below while another prefers the breeze and views above. It also helps if you are not comfortable in enclosed spaces.

The lower cabin has air conditioning, which is welcome in Rhodes during the warmer months. However, comfort depends on how crowded the boat is. When everyone heads downstairs for the fish show, seating can become tight, and some people have found the cabin warm or sticky despite the cooling system.

Starting at Platia Eleftherias and Mandraki Harbor

The meeting point is at Mandraki Port, at the Poseidon Submarine berth opposite the Bank of Greece building. The listed starting location is Platia Eleftherias, in the center of Rhodes Town.

Mandraki is a useful place to begin because it puts you close to several major sights. You can walk here from the Old Town, and the port itself is part of the sightseeing. Before the boat moves, take a moment to look around at the harbor entrance and the waterfront.

The cruise lasts 45 minutes, so it fits neatly into a morning or afternoon of exploring. It is particularly useful when you want a water activity without giving up half a day. One past passenger arrived early and was allowed to relax on the boat while waiting, though I would not treat that as a guaranteed part of every departure.

There is a bar onboard, but drinks are not included. Bring your budget in mind, especially if you are traveling with children who spot refreshments before the boat leaves.

Ten minutes around Mandraki Harbor

The first part of the route is a slow cruise around Mandraki Harbor. This gives you a new view of Rhodes Town, especially if you have already walked along the waterfront.

From the boat, you can see the harbor, the town, and the fortifications from the waterline. The change in viewpoint matters. On land, the Old Town walls feel massive and solid. From the sea, you see how they form a long defensive edge around the historic center.

The audio commentary provides information in English and German, while the live guide is in English. The commentary adds some context about Rhodes, including local sights and historical figures. Several people found the recorded explanation difficult to hear, either because the volume was low or music was playing at the same time.

My advice is simple: treat the commentary as a bonus, not the main reason to book. Keep your eyes outside, and ask the crew if you need help identifying a landmark.

The former Colossus site and the Palace of the Grand Master

As the boat continues, the route points out the location associated with the Colossus of Rhodes. The ancient statue no longer exists, but the site carries a strong sense of place because it marks one of the most famous stories linked to the island.

You also get views toward the Palace of the Grand Master of the Knights of Rhodes. The palace is one of the major landmarks of the Old Town, and seeing it from the sea gives you a useful sense of its position within the medieval city.

The boat does not stop for a land visit. You are looking from the water, so keep your expectations in check. This is a sightseeing pass, not a detailed guided tour of the palace or ancient statue.

Still, this portion works well for first-time visitors. You get a quick orientation to the historic center before the focus shifts from stone walls to the sea.

Elli Beach, the Tourist Harbor, and the Old Town walls

The route also includes Elli Beach and the Tourist Harbor. These views add variety to the trip. You see the more open waterfront, the busy harbor areas, and the fortified Old Town in one short outing.

I like this part because it gives you a visual map of Rhodes Town. Afterward, you may better understand how Mandraki Harbor, the beaches, the commercial port, and the medieval center fit together.

The deck is the best place for this section if the weather is pleasant. You can enjoy the sea air and take wider photos without reflections from the underwater windows. The cabin is better for the seabed and fish, but the deck wins for town views.

The boat can become busy, especially when passengers occupy more than one seat. If you want a particular spot, arrive with enough time to board calmly. Staff have helped reorganize seating when the lower cabin became crowded, but it is still wise to expect a popular family attraction rather than a quiet private cruise.

The underwater fish-feeding show

The central event comes when a crew diver enters the water and feeds the fish beside the viewing windows. This is the moment that gives the cruise its character.

You may see hundreds of colorful fish gathering around the diver. The spectacle is easy to follow, even for young children, and the crew makes it interactive by bringing the action close to the glass. Some trips have also included underwater photos or video of passengers, with images shared through the operator’s social media channels. That has not been promised as an included feature, so enjoy it if it happens rather than counting on it.

The fish viewing takes place in one main area. You should not expect a large range of sea life or a long ride through several underwater habitats. One account described mostly the same kind of fish, while others saw a seabed with rocks and sea grass and, on one trip, an octopus.

Water conditions also matter. On a clear day, the windows can provide a good look at the fish and seabed. At other times, cloudy water or dirty glass can reduce the effect. A few people found the windows less clean than they hoped, so this experience is best approached as a fun harbor wildlife encounter, not a guaranteed crystal-clear view.

How to get the best view below the surface

If the underwater show matters to you, check the departure time carefully. The 18:30 cruise does not include the diver feeding the fish.

Once the boat reaches the viewing area, move downstairs promptly if you want a seat. The lower cabin is where the main action happens, and it can fill quickly. If you are traveling with a child, sit where the windows are easiest to see rather than assuming everyone will have an equally clear view.

You can also split the experience. Watch the fish from below, then go upstairs for the final town views. The crew allows you to choose between the cabin and deck, which makes the cruise more flexible than a fixed-seat boat ride.

Bring a camera, but expect reflections through the glass. You will usually get better photos of Rhodes from the open deck. For the fish, hold your camera close to the window and avoid using flash unless the crew says it is acceptable.

Comfort, accessibility, and the onboard setup

The air-conditioned cabin is designed for comfort, but it is not spacious when full. Several people found the lower area cramped, and one parent had difficulty finding seats with an eight-year-old until the crew helped organize the group.

That is the main practical weakness of the experience. The cruise is short, so the discomfort does not last long, but anyone sensitive to heat or crowded spaces should plan to spend part of the trip outside.

The vessel is wheelchair accessible, which makes it a useful option for visitors who cannot manage a more demanding boat excursion. Exact seating and boarding needs are worth confirming when booking, especially if you require specific assistance.

The trip is also easy for families. It has no long walk, no strenuous activity, and no need to swim. Children get a clear event to watch, while adults receive harbor views and a little local history.

Is $23 good value for 45 minutes?

At around $23, this is one of the easier Rhodes activities to recommend on price alone. You receive a boat ride, views of several major landmarks, underwater viewing, the fish-feeding show, and access to a bar onboard.

The value is strongest if you want a short activity between visits to the Old Town, or if you have children who may not enjoy a long historical tour. You can see Rhodes from the water and still have most of the day available for museums, beaches, and the medieval streets.

The value is weaker if you expect a large submarine, professional marine commentary, or a long stretch of untouched sea. The underwater section is focused and fairly brief, and the commentary may be hard to hear.

Even with those limits, the price feels fair. It is a simple, cheerful excursion rather than a luxury cruise. Several passengers described it as a good way to fill an hour, and that is exactly how I would frame it.

Who should book this Rhodes cruise?

I would recommend the Poseidon Submarine especially for:

• Families with children who want an easy sea activity.
• First-time visitors looking for a quick view of Rhodes from the water.
• Anyone with a short gap in their sightseeing schedule.
• Couples who want a relaxed harbor ride without committing to a full-day boat trip.
• Visitors who enjoy fish and simple wildlife encounters but do not want to snorkel.

I would be more cautious if you need a quiet, spacious boat or want to see many kinds of marine life. The lower cabin can be crowded, the water may be cloudy, and the fish viewing centers on one feeding area.

For the best experience, choose a departure before 18:30, arrive with time to board, and be ready to move between the deck and lower cabin. That small bit of planning addresses most of the common frustrations.

Final verdict: book it for the views and the fish

The Poseidon Submarine cruise is a good-value, family-friendly 45-minute outing with two clear pleasures: Rhodes seen from the sea and a diver feeding fish beside the windows.

It is not the right choice if you want a serious underwater expedition. But if you want something short, affordable, and easy to fit around the Old Town, I would book it. Choose a time with the underwater show, head below early for a clear view, and keep your expectations realistic. The boat may look modest, but the combination of fortifications, sea air, and colorful fish makes the hour well spent.

FAQ

Where does the Rhodes submarine cruise depart from?

It departs from Mandraki Port at the Poseidon Submarine berth, opposite the Bank of Greece building. The listed starting point is Platia Eleftherias in central Rhodes Town.

How long is the Poseidon Submarine cruise?

The cruise lasts 45 minutes. The route includes harbor sightseeing, views of Rhodes Town landmarks, and time for marine life viewing.

Does the boat actually go underwater?

The vessel remains above sea level. Its underwater observatory section sits about 2.5 meters below the surface, where you can look through large windows.

Will I see a diver feeding fish?

The cruise includes a diver feeding fish beside the underwater windows, except for the 18:30 departure, which does not include the feeding show.

What sights can I see from the boat?

The route includes Mandraki Harbor, the former site of the Colossus of Rhodes, the Palace of the Grand Master of the Knights of Rhodes, Elli Beach, the Tourist Harbor, and the walls of the Old Town.

Is the cruise wheelchair accessible?

Yes, the activity is listed as wheelchair accessible.

Is an audio guide included?

Yes. An audio guide is included in English and German, and a live guide is available in English. The audio commentary may be difficult to hear at times, so the main experience is best enjoyed through the views and underwater show.