Zakynthos: Private Boat Tour Marathonisi, Keri Caves & Mizithres

Summary

Swim with turtles & drift through blue caves on Zakynthos’ south coast

You’ll spot loggerhead turtles near Cameo Island, swim over hidden nests at Marathonisi Turtle Island, drift beneath bright arches of Keri Caves, and reach Mizithres Rocks by private boat. With a local skipper guiding you—and plenty of time to snorkel or float—you’ll catch those small moments you can’t plan for but end up remembering most.

Step-by-step itinerary

Day 1 — Zakynthos South Coast Boat Tour

• Meet skipper at Keri Harbour
• Spot loggerhead caretta turtles near Cameo Island
• Swim at Marathonisi Turtle Island
• See Marathonissi Caves en route
• Explore Keri Blue Caves and swim
• Visit Mizithres Rocks and swim/snorkel

Top questions

How long is the Zakynthos private boat tour?

The private boat tour lasts about 3 hours but can be flexible depending on your group’s preferences for swim stops and turtle spotting.

Does this tour include turtle spotting?

Yes, you’ll have a chance to spot loggerhead Caretta Caretta turtles near Cameo Island with help from your local skipper.

Is snorkeling equipment provided on this tour?

Yes, swimming masks are included so you can snorkel at Marathonisi Turtle Island or other stops along the way.

How many people can join this private boat tour?

The tour is designed for up to 5 people—ideal for couples, families with kids, or small groups of friends.

Are life vests available during the trip?

Yes, life vests are provided for all guests on board.

Can we personalize our swim stops?

Yes, since it’s a private tour your skipper will adapt swim stop durations based on what your group prefers.

Where does the Zakynthos boat tour start?

You’ll meet your personal skipper at Keri Harbour on Zakynthos’ south coast.

What’s included

Your day includes a private boat with local skipper starting from Keri Harbour, swimming masks and life vests for everyone onboard, fuel covered so you don’t worry about extra costs, plus a waterproof phone case (trust me—you’ll want one). Swim stops are flexible depending on how long you want to linger or search for turtles together.

What’s the experience like?

I’d never seen water that clear before—almost glassy, like someone had turned up the color dial just for us. Our skipper, Nikos, met us at Keri Harbour with this easy grin and a waterproof phone case (which I ended up needing more than once). He pointed out Cameo Island as we set off, but honestly I was too busy scanning for turtles—someone shouted “there!” and suddenly there it was: a Caretta Caretta turtle just gliding past the boat. It felt weirdly peaceful to watch her surface and dip under again. We all went quiet for a second.

Marathonisi Turtle Island looked almost fake from a distance—like those postcards you don’t really believe until you see them. Nikos told us about the eggs hidden in the sand (he called them “the island’s little secrets,” which made my son laugh), then handed out masks for snorkeling. The water was cold at first but then perfect. I remember the smell of sunscreen mixing with salt and something sweet from someone’s bag—peaches maybe? We floated near the caves and I tried to pronounce “Marathonisi” properly; Nikos just shook his head and grinned.

The Keri Caves were next—arches so white they almost hurt your eyes in the sun, and that echo when you swim under them. My daughter kept yelling her own name to hear it bounce back. The boat rocked gently while we swam, and I got this sudden urge to just stay there all afternoon. But then we headed toward Mizithres Rocks, which look even bigger up close than in pictures. Only boats can get here; I liked that part—it felt like we were in on some secret (even if half of Zakynthos probably comes here in July). Swimming at Mizithres Beach was wild—the color of the water is still stuck in my mind.