The Gaza-bound Sumud flotilla appeared to have traveled around 50 miles from Barcelona on its first night of sailing. It had been delayed by heavy winds and was thus forced to leave for a second time on Monday afternoon.

By mid-Tuesday, the vessels in the group appeared on open-source vessel tracking sites, such as Vessel Finder, as being 45 nautical miles from Barcelona.

The flotilla has already faced several problems. Heavy winds with gusts up to 30 knots were too much for some of the vessels. The 20 ships that left apparently included several boats that were either unable to brave the winds or were not seaworthy for these open sea conditions.

Most of the vessels, however, are more sturdy. Several of them consist of larger ships. For instance, one boat seen on a video posted by the Sumud group showed a vessel named Family. This same vessel, as shown on ship tracking sites, is said to be 23 meters long and six meters wide.

A second vessel seen on a video rereleased by Sumud activists appeared to show a ship named the Alma Explorer Yacht. On vessel tracking sites, a similarly named ship is described as being 33 meters long and eight meters wide at the beam. An email to a website that appears to charter a vessel by the same name was not returned as of press time.

Activists including Greta Thunberg, stand on a boat that is part of the Global Sumud Flotilla, a humanitarian expedition to Gaza, as seen from the port in Barcelona, Spain August 31, 2025
Activists including Greta Thunberg, stand on a boat that is part of the Global Sumud Flotilla, a humanitarian expedition to Gaza, as seen from the port in Barcelona, Spain August 31, 2025 (credit: BRUNA CASAS/REUTERS)

The other vessels that appear on open-source vessel tracking sites are of varying lengths, from sailboats that are 14 meters long to a converted fishing vessel that is 17 meters long. Sailboats in this class would have no problem with 30-knot gusts. The actual weather has been relatively mild in September.

The 'electromagnetic storm'

One activist aboard the Sumud flotilla posted online that it had lost radio communications due to an “electromagnetic storm.” The post said that the storm caused some “damaged” boats to turn back.

According to the post, there are now only 14 ships in the line of sight of the flotilla pack. The 14 vessels are continuing toward Tunisia, which is some 400 nautical miles away.

At their current speed, which is claimed to be around 3.2 knots, it will take them five days to reach Tunisia’s coastline. However, if they can increase their speed, it should take them only a few days.

The question is why larger vessels, which probably use marine diesel engines, cannot go faster than a few knots. They appear to be hindered by the slower boats in the group, possibly the sailboats. To conserve fuel, these sailboats will be making speed with the wind, which, if it is light, keeps them at three to five knots.

As for the reports that the flotilla lost communications, they seem bizarre. A storm would not knock out marine VHF radios, which should have a range of up to 10 miles. A larger craft will have better communications equipment and range, which should enable it to communicate at a much greater distance using satellite phones or radios. A chart of the location of the flotilla showed that its lead boat was only 20 miles from the lagging boats at press time.

Nevertheless, a post on social media by the Sumud flotilla on Tuesday said that “due to extreme weather conditions last night, five of our smaller vessels turned back for safety reasons. We are relieved to confirm that everyone is safe and accounted for. The mission continues.”

That report added that the initial flotilla consisted of 24 boats. Now, there are only 19 left. It named one of the vessels as Sirius, “A World War I-era sailing vessel that is 107 years old and carries 28 passengers, including seven crew members, which is one of the 19 ships continuing toward Gaza in fair weather.”

The flotilla is expected to be joined by dozens of other vessels from Italy and Tunisia as it continues on its way. Considering the attrition rate of the initial Barcelona group of the flotilla, the estimate that it may have 70 ships appears exaggerated.

It still has around 1,900 miles to go to get to the coast of Israel. The flotilla will have to round Menorca next, which is one of Spain’s Balearic Islands. Forecasts indicate winds of six to 10 knots over the next day. The flotilla was set to pass the coast of Menorca late Tuesday evening.