Mr Shapira will join the US-flagged ship The Audacity of Hope in the flotilla. Holocaust survivor Hedy Epstein is among 50 American and Jewish peace activists who will be on board the same vessel. Epstein, 86, has tried to reach the Gaza Strip several times before, but has been prevented on each occasion.
"We cannot know whether we will reach the Gaza Strip, but we have one goal: to help the innocents in Gaza even if Israel sinks all the ships and kills us all," said Shapira.
The Audacity of Hope was barred from leaving the port of Athens on the grounds that it lacks the necessary licences but this has been denied by the flotilla's organizers. Such a delaying tactic results from Israeli pressure, they said, and is intended to stop the ship from reaching the Gaza Strip.
One of the organizers of the American ship's participation in the flotilla, Dror Feiler, said that if The Audacity of Hope is prevented from taking part, there is in any case a large number of other ships now on their way to Gaza.