Kos Three Islands Boat Trip: Kalymnos, Pserimos and Plati

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The “3 islands” cruise is the classic boat day out from Kos: a stop on Kalymnos, a swim at the uninhabited islet of Plati and an hour on the small beach island of Pserimos, back in Kos harbour by late afternoon. Most boats leave from Kos Town harbour around 09:30 to 10:00, include lunch on board or at a taverna, and pick up from hotels across the island. If you only want Kalymnos, the local ferry from Mastichari is a simple independent alternative.

Short answer

• The three islands: every operator we checked lists Kalymnos, Plati and Pserimos. Where you stop on Kalymnos differs: some boats go to Vathy, a narrow fjord-like inlet, others to the main town and port of Pothia.
• Departure: the boats we found sail from Kos Town harbour. Hotel transfers bring guests in from resorts such as Mastichari, Tigaki, Marmari and Lambi; Kardamena is the departure port for Nisyros trips, not for the 3 islands cruise.
• Typical day: boarding around 09:30 to 10:00, return around 17:00, 7 to 7.5 hours in total (as of October 2026, according to operator and GetYourGuide listings).
• Usually included: the cruise, swim stops and a simple lunch (souvlaki, salad, bread, with vegetarian options). Drinks are usually extra; hotel transfer is included on some listings and optional on others.
• Season: one local operator lists the trip from May to October. Check availability for your dates, especially at the edges of the season.
• Do it yourself: ANEM and other operators run short crossings from Mastichari to Kalymnos, about 30 to 45 minutes each way, with several sailings a day.

Where the boats go

All three stops are Greek islands north of Kos, so there is no border to cross for holidaymakers already on Kos. Pserimos belongs administratively to Kalymnos.

Kalymnos: Vathy or Pothia

Kalymnos is the largest and most interesting of the three. Which part you see depends on the boat.

• Vathy: listings for the Odyssey and Poseidon boats stop at Vathy, on the east coast. The valley ends in a long, narrow inlet that Discover Greece compares to a fjord, with the small harbour of Rina at its head. Greeka notes that Vathy has no real beach, but you can swim from steps along the harbour. Expect about an hour ashore.
• Pothia: the pirate-style boats and some agency tours stop at Pothia, the island’s capital and main port. Here you have time to walk the waterfront, look into one of the few remaining sponge workshops and, if time allows, the Maritime and Folklore Museum on the seafront, which tells the story of the island’s sponge divers. One operator gives 1 hour 30 minutes in Pothia; another about 55 minutes.

If Kalymnos is the part that interests you most, check which port your boat uses before you book.

Plati

Plati (also spelt Platy) is a small uninhabited islet. It is purely a swim and snorkel stop: the boat anchors, you jump in, and the crew often runs a happy hour or serves drinks on board. Listings give it between about 20 minutes and an hour. Several tour pages and reviews mention dolphins on this stretch, but none promises them.

Pserimos

Pserimos is one of the smallest inhabited islands in the Dodecanese. Greeka puts the permanent population at about 30 people, nearly all in the harbour village of Avlakia, which has the island’s only organised beach, a couple of tavernas and a few rooms to rent. On the 3 islands trip you get roughly an hour here to swim from the sandy beach in front of the village. There are no ATMs on Pserimos, so bring cash if you plan to buy anything.

A typical day

The order of stops varies by boat. These timings come from operator sites and GetYourGuide listings as of October 2026; all say the route can change with the weather.

Sailing time between the stops adds up to around three hours. The first leg from Kos takes about an hour; the hops between the islands are 20 to 45 minutes each. One reviewer on a shared Kalymnos and Pserimos cruise noted that the time at sea felt longer than the itinerary suggests, so allow for a long day.

If you book with hotel transfer, add up to 45 minutes at each end for pick-up and drop-off.

What is included and what is not

Listings differ, so read the details of the one you book. Across the tours we checked:

• Included: the cruise, the three stops, swim stops, and lunch. Lunch is usually a barbecue on board (chicken or pork souvlaki, Greek salad, tzatziki, bread), with vegetarian versions on request. The Kos4all tour lists lunch in a restaurant, and the S Tours version serves lunch at a taverna on Kalymnos.
• Sometimes included: hotel transfer (included on the Odyssey and pirate cruise listings, optional or extra on others), towels, coffee.
• Usually extra: drinks from the onboard bar. One listing says you cannot bring your own drinks on board. Snorkelling gear and tips are also extra on at least one boat.
• Optional on Kalymnos: Exas mentions a 20-minute tourist train in Pothia at 4 euros per person (as of October 2026).

The Exas cruise is listed from 30 euros per person (as of October 2026). GetYourGuide prices vary by date and option; check the live price on the listing.

Which boat suits you

The boats fall into two broad types. The pirate-themed boats (Barco de Pirata, Pirates of Kos, Pirate of the Aegean) market themselves as family cruises, with music, a water slide on some boats and a party feel at the Plati stop. The traditional wooden boats such as Odyssey and Poseidon are calmer. Larger boats can feel crowded on busy days; one reviewer mentions this on the Poseidon cruise.

Organised tours

These are real 3 islands cruises from Kos listed on GetYourGuide. Booking direct with a local operator at the harbour or through your hotel is also common and can be cheaper; compare what is included rather than the headline price.

Season and weather

Kos4all lists its 3 islands cruise from May to October. Other operators describe a daily cruise without naming dates, and GetYourGuide shows availability by date, so check your dates before you plan around it.

Wind matters more than the calendar. Several October reviews of the Odyssey cruise describe choppy seas and a cool crossing; one recommends a hoodie or blanket. If you are prone to seasickness, take precautions before you board. Operators may change the order of stops or skip one in rough weather.

For general sailing seasons around the Dodecanese, see the ferry season calendar.

Doing it yourself: Mastichari to Kalymnos

If Kalymnos is the island you really want to see, the local ferry from Mastichari, on the north coast of Kos, gets you there on your own schedule.

• Operators: ANEM Ferries, based in Mastichari, says it has connected Kalymnos and Kos with frequent daily sailings since 1986 and publishes its timetable and online booking on its own site. NetFerry also lists A.N.E. Kalymnou and Lafasi on the route.
• Crossing time: about 30 to 45 minutes, according to climbkalymnos.com and NetFerry.
• Frequency: several sailings a day, every day of the week, according to NetFerry. ANEM publishes separate timetables for 1 to 24 October and 25 to 31 October 2026, so times change through the season.
• Arriving: the ferries land at Pothia, from where buses and taxis run to Vathy and the west coast. Climbkalymnos.com puts Mastichari about 7 km from Kos airport.
• Getting to Mastichari: KTEL island buses run daily between Kos Town and Mastichari, according to the Kos municipality; check the current timetable on ktel-kos.gr.

The ferry route suits travellers who want more time on Kalymnos, for example to visit Chorio castle, the museums or Telendos. You give up Plati and Pserimos and the lunch on board. Pserimos is harder to reach independently; we could not find a regular public ferry timetable for it on an official source.

Other boat trips from Kos

• Nisyros volcano: the other classic full-day trip, sailing from Kardamena on the south coast to Nisyros, with a bus up to the volcanic crater and free time in Mandraki. The GetYourGuide listing below gives pick-ups across the island from 08:00 and a return boat at 16:00, with a 5 euro crater entrance fee paid on the spot (as of October 2026).
• Bodrum day trip: a short ferry crossing to Turkey from Kos harbour. See the Kos to Bodrum day trip guide for entry rules and timings, and the Bodrum to Kos ferry page for the crossing itself.

Tips

• Check the Kalymnos stop. Vathy is quieter and scenic; Pothia has the sponge workshops and museum.
• Bring ID. The pirate cruise listing asks for a passport or ID card, or a copy or photo of it, including for children.
• Bring cash. Drinks are usually extra and there are no ATMs on Pserimos.
• Pack for swimming and sun: swimwear, towel if not provided, sunscreen, hat and a warm layer for the return crossing.
• Tell the operator in advance if you need a vegetarian or gluten-free lunch.
• Mobility: one listing marks the trip as unsuitable for people with mobility impairments while also labelling it wheelchair accessible. Ask before booking.
• With children: the pirate boats are designed for families; see Greek islands with kids from Turkey for wider tips, and where to stay in Kos if you are still choosing a base.

FAQ

Which islands does the Kos 3 islands boat trip visit?

Kalymnos, Plati and Pserimos. On Kalymnos, some boats stop at Vathy and others at Pothia, so check the listing.

How long is the 3 islands cruise from Kos?

About 7 to 7.5 hours. Boats board around 09:30 to 10:00 and return around 17:00, as of October 2026.

Is lunch included?

On the tours we checked, yes. It is usually a barbecue on board; a few tours serve lunch at a taverna. Drinks are normally extra.

Does the boat leave from Kardamena or Mastichari?

The 3 islands cruises we found sail from Kos Town harbour, with hotel transfers from the resorts. Kardamena is the port for Nisyros trips, and Mastichari for the ferry to Kalymnos.

Can I visit Kalymnos without a tour?

Yes. Ferries run several times a day from Mastichari to Pothia, a crossing of about 30 to 45 minutes. Check ANEM’s own timetable for current times.

Do I need a passport?

All three islands are part of Greece, but at least one operator asks for a passport or ID card, or a copy, so carry one.

Timetables, prices and entry rules change; check the official source before you travel.

Sources

• Kos4all: Kos 3 island cruise boat trip (accessed Oct 2026)
• Exas Travel Service: 3 Island Cruise (accessed Oct 2026)
• S Tours: 3 Island Cruise (North) (accessed Oct 2026)
• ANEM Ferries: Kalymnos–Mastichari (accessed Oct 2026)
• NetFerry: Mastihari (Kos) to Kalymnos (accessed Oct 2026)
• Climb Kalymnos: Kalymnos info (accessed Oct 2026)
• Kos Municipality: Getting around (accessed Oct 2026)
• KTEL Kos (official site) (accessed Oct 2026)
• Kalymnos Municipality: Maritime and Folklore Museum (accessed Oct 2026)
• Greeka: Pserimos island (accessed Oct 2026)
• Greeka: Vathy, Kalymnos (accessed Oct 2026)
• Greeka: Kalymnos ports (accessed Oct 2026)
• Greeka: Kalymnos buses (accessed Oct 2026)
• Greeka: Kalymnos sponge workshop (accessed Oct 2026)
• Discover Greece: 8 top things to do in Kalymnos (accessed Oct 2026)
• GetYourGuide: From the Port of Kos, Full Day Boat Cruise to 3 Islands (accessed Oct 2026)
• GetYourGuide: Kos Pirate Cruise, 3 Islands, Swimming Stops & Lunch (accessed Oct 2026)
• GetYourGuide: From Kos, 3-Islands Boat Trip with BBQ on Pirate Boat (accessed Oct 2026)
• GetYourGuide: Kos Town, Kalymnos & Pserimos Day Cruise (accessed Oct 2026)
• GetYourGuide: From Kos, Nisyros Island Volcano and Panagia Spiliani (accessed Oct 2026)