Two markets answer this question in Greece and they share almost nothing but the word. One is a small boat for a day out of a harbour on an island you are already staying on. The other is a yacht for a week from a charter base, with a certificate checked at the desk and a deposit held. The prices are not comparable and neither are the requirements.
The day market on the islands
Most Greek island harbours rent small motorboats by the day or half day, and the marketplaces aggregate them: Click&Boat and SamBoat both list Greek boats with a from price against each one. Those floors are set by whichever listing is cheapest at that moment and move as boats sell, so they price the entry to the market on the day you look rather than a particular boat. Small engines can usually be hired without a license; anything larger cannot.
The week market from the charter bases
Nautilus Yachting states that a one week charter on a two to three cabin monohull starts around 900 pounds in low season. Istion Yachting lists catamarans from 3.510 EUR a week out of Athens. The Moorings publishes a 7 day charter for 2 from $2,634. You sleep aboard, you move between islands, and you return the boat to the base you left from.
What renting a boat in Greece asks of you
For a charter yacht, a recognized skipper's certificate and a VHF operator's license for the named skipper, with the originals checked at handover and a second competent crew member declared. For a small day boat under a stated engine power, usually nothing. The gap between those two positions is the single most important thing to establish before you pay a deposit on anything.
Which one suits your week
Staying in a hotel on Paros and wanting an afternoon in a bay: the day market, booked locally or through a marketplace. Wanting to see four islands and sleep aboard: a charter week from Athens, Lefkas or Kos. The mistake that costs most is pricing the second by multiplying the first, which produces a figure no Greek company would ever charge.
Questions people ask about rent a boat in Greece
How much does it cost to rent a boat in Greece?
For a week, Nautilus Yachting says a two to three cabin monohull starts around 900 pounds in low season and Istion lists catamarans from 3.510 EUR. Day boats are listed on marketplaces against floors that move as listings sell.
Can I rent a boat in Greece without a licence?
Small motorboats under a stated engine power, usually yes. Any charter yacht needs a recognized skipper's certificate and a VHF license, checked as originals at handover.
Is it cheaper to rent by the week in Greece?
Per day, substantially. A charter week is a fleet contract with a Saturday handover and a deposit; multiplying a day rate by seven produces a figure nobody charges.