Humanitarian aid transported by Greta Thunbergs second flotilla wont even reach Gaza because of a lack of docking facilities and Israels "lawful" blockade, a maritime expert has said.As the Swedish activist's boats left Barcelona Sunday, Thunberg was joined by figures, including Game of Thrones actor Liam Cunningham and former Barcelona mayor Ada Colau.The Global Sumud Flotilla, consisting of about 70 boats, is carrying aid including food, water and medicine and hoping to bring this to civilians in the Gaza Strip.The flotilla is expected to be joined by more boats before they reach Gaza around Sep. 14 or 15.ISRAEL BLOCKS HUMANITARIAN AID INTO GAZA AFTER HAMAS REJECTS CEASEFIRE EXTENSION PROPOSAL"The whole world knows that this is coming and the IDF is going to maintain a security perimeter out in the water to protect the beaches of Gaza," Professor James Kraska, S.J.D., told Fox News Digital."There aren't any port facilities in this area to unload anything and Gaza lacks a port sufficient to receive such a large flotilla. There's a small fishing port, but that's inadequate."The U.S. built a temporary port at considerable expense, about $200 million, and dismantled it because the weather and meteorology in the area made it unsustainable," the U.S. Naval War College professor confirmed.Thunbergs second attempt at leading a flotilla comes amid the ongoing war in Gaza City that has killed more than 63,000 people.GRETA THUNBERG DEPORTED FROM ISRAEL AFTER GAZA-BOUND 'SELFIE YACHT' WAS SEIZEDAt a press conference in Barcelona before she left, Thunberg framed the mission as an act of survival."The story here is about Palestine. The story here is how people are being deliberately deprived of the very basic means to survive," Thunberg said, alleging that Israel was violating international law by "unlawfully intercepting boats in international waters" and preventing humanitarian aid from reaching civilians.This is not Thunbergs first attempt at delivering aid. In June, she was deported after her ship, the Madleen, was stopped by Israeli forces along with 11 others on board.FOX NEWS ANTISEMITISM EXPOSED NEWSLETTER: GRETA'S ANTI-ISRAEL STUNT GOES AWRYProfessor Kraska emphasized that having Israel's blockade is a lawful operation during an armed conflict to prevent vessels entering, but it must meet certain requirements, including notice, effectiveness, and impartial enforcement."Ultimately, there is authority for Israel to defend the blockade," Kraska said. "But its not just the law politics and practical realities are involved as well. Both sides are weighing those dimensions."Israel, however, maintains that its maritime security operations, which look like a blockade, are a lawful measure of war and will act to prevent ships from docking."There is not one controlling narrative: there is international law, the political situation and the tactical dimension," he added.