Activists trying to break Israel's naval blockade of Gaza scored their first gain in days when a small French pleasure boat slipped out of Greek waters Tuesday bound for Palestinian shores.

The “Dignite al Karama” is the only boat in a planned flotilla organized by pro-Palestinian activists to make it out of Greek ports in recent days.

Greece announced a ban last week on vessels headed to Gaza and arrested the captain of an American ship for leaving port without permission over the weekend. The Associated Press reported on Tuesday that a Greek court released the American from custody.

Activists say the French boat – a 9-meter motor cruiser – is carrying eight passengers and is expected to be off Gaza within days.

Organizers say the boat eluded the Greek coast guard because it left from a port other than Piraeus, where many of the flotilla vessels have been moored.

On Monday, Greek authorities blocked the ship Tahrir as it tried to leave the island of Crete in defiance of a government ban on flotilla vessels.

The Tahrir is named after a Cairo square at the center of an Egyptian anti-government uprising earlier this year. The ship was carrying activists from Canada and other nations when it was intercepted.

Organizers had planned to send about a dozen vessels from Greece to Gaza late last month, carrying hundreds of activists and humanitarian aid for the Palestinians.

But the flotilla has suffered a series of setbacks, with some ships facing technical and bureaucratic problems. The activists accuse Israeli spies of sabotaging their mission, a charge Israel denies.

Israel has vowed to enforce a naval blockade it imposed on Gaza in 2007 to stop weapons from reaching Hamas militants that run the territory.

The Greek government has offered to deliver the flotilla's humanitarian cargo to Gaza through organized channels that include Israeli ports, where the cargo is screened for potential weapons. Organizers have rejected the idea.