Best eSIM for Greece in 2026: Athens, Santorini, Mykonos — and ferry dead zones

Greek cellular coverage has one quirk no one warns tourists about: between islands, you spend 30-90 minutes on the open Aegean with no signal at all. Even Cosmote, the strongest network, drops to nothing about 5 km off Santorini. Plan your ferry rides assuming you'll be offline, and download maps before you board.

Airport SIM kiosks at ATH and JTR

Athens (ATH) has Cosmote, Vodafone and Nova kiosks in arrivals — they sell tourist SIMs for EUR 15-30 with 10-25 GB. Santorini (JTR) and Mykonos (JMK) have smaller kiosks at hotel desks at 30-50% markup. An eSIM from MobileXY's Greece plans activates before you land and avoids both.

How much data?

• 4-day Athens city break: 3-5 GB — Acropolis tickets, taxi apps, Instagram.
• 1-week island hop (2-3 islands): 10 GB. Add buffer for offline-map downloads.
• 2-week sailing trip: 20 GB. Even with ferry blackouts, you'll burn through it in port WiFi gaps.

Coverage by network

• Cosmote: Best on Cyclades (Santorini, Mykonos, Naxos, Paros) and Crete. Strongest 5G in Athens.
• Vodafone: Wins in Thessaloniki and the Peloponnese. Decent on Rhodes and Corfu.
• Nova (former Wind): Cheapest. Strong on mainland Greece, patchy on smaller islands.

The ferry-blackout problem

Blue Star and Hellenic Seaways ferries cross open water for 1-4 hours. Cellular signal drops about 5-10 km from any coastline and doesn't return until you're approaching the next port. WiFi on board exists but costs EUR 5-10 per crossing and crawls. Before you board:

• Download offline maps for your destination island.
• Save your hotel address as a screenshot — a Maps deep-link won't open without data.
• Tell your group when to expect you back online — usually 30-60 minutes before arrival.

Quick verdict

For a 1-2 week Greek trip, buy a 10 GB plan that runs on Cosmote's network — it's the only one that reliably reaches both Crete and the Cyclades. Check MobileXY's Greece plans. If you're combining Greece with Italy or Turkey, our Europe regional bundle covers all three.