Agios Sostis: Marathonissi, Keri Caves, and Turtle Spotting

Name: Agios Sostis: Marathonissi, Keri Caves, and Turtle Spotting
Brand: GetYourGuide
Price: 29.00 USD
Availability: InStock
Rating: 4.40 (426 reviews)

4.4 (426 verified reviews)

The sand bar on Marathonisi with a boat moored in the shallows

Aerial view of Cameo Island and its footbridge at Agios Sostis harbour

A sea cave mouth in the white limestone of the Keri cliffs

A loggerhead turtle swimming over the sandy seabed in clear water

About This Experience

At $29 this is the lowest price on the south coast for a proper marine-park circuit, and a compact one: a glass-bottom boat with a shaded cabin and a rear sundeck, a maximum of about twenty passengers, three hours, no pickup.

The boat crosses Laganas Bay looking for loggerheads, then heads for the Keri Caves area. The swim here is at Oasis Bay and close to the cave — the listing is honest that there is no swimming inside the cave itself, which is worth knowing before you compare it with the speedboats. The second stop is Marathonisi, with free time to swim off the small open section of beach or buy a drink at the bar; the rest of the island is a protected nesting ground.

It suits anyone staying in Laganas or Kalamaki who wants turtles, the caves and Turtle Island without paying for a speedboat or pickup. Bring your own food and water — nothing is served on board.

Highlights

The lowest-priced south-coast cave and turtle trip we list, from $29
Look for loggerhead turtles through the glass floor in the National Marine Park
Swim at Oasis Bay beside the Keri Caves
Free time on Marathonisi, Turtle Island, with a bar for snacks
A small boat of about twenty passengers with shade and a sundeck

What's Included

✓ Glass-bottom boat ticket
✓ Marathonisi visit and swim stop
✓ Keri Caves viewing and the Oasis Bay swim stop

Not Included

Hotel pickup and drop-off
Food and drinks (available to buy on Marathonisi)
Swimming inside the cave

What to Bring

Swimwear and towel
Food and water
Snorkelling gear
Sun hat, sunglasses and sunscreen

Good to Know & Caveats

Turtle sightings are not guaranteed, and boat traffic in the bay can make them harder to see
The swim is beside the Keri Caves, not inside them
Only a small part of Marathonisi's beach is open — the rest is a protected loggerhead nesting ground
No pickup: Agios Sostis is a few minutes from Laganas by car or on foot along the beach road

Not Suitable For

Wheelchair users

Meeting Point

Look for the Nautilos flag in front of the boat at Agios Sostis harbour near Laganas; the captain welcomes you aboard.

What Travelers Say

Rated 4.4/5 by 426 verified GetYourGuide travelers.

That was really great, and we go often. The captain alone was just so experienced, funny and accommodating. Maximum of 20 people and 3 hours is completely sufficient
— Marika, July 16

Everything was really beautiful. The only thing that was a bit disappointing was the turtles because of the large number of boats!
— Ginevra Aurora, June 17

Really good value for money, the captain was amazing he even let me at the front of the boat to do some filming.
— Ben, June 3,

Frequently Asked Questions

Do we go inside the Keri Caves?

No. The boat views the caves and stops to swim at Oasis Bay in the caves area. If swimming inside a cave matters to you, the speedboats from the same harbour do that.

Is hotel pickup included?

No. The boat leaves from Agios Sostis harbour beside Laganas; it is walkable from Laganas beach or a short drive with parking at the quay.

How many people are on the boat?

About twenty at most, with a shaded cabin and a rear sundeck.

Can we see the turtles?

Usually, especially in the morning, but they are wild and there are many boats in the bay in high season. One reviewer found the crowds made sightings harder.

What is on Marathonisi?

A small open section of beach for swimming and a bar selling drinks, snacks and ice cream. The rest of the beach is fenced off as a nesting zone.