|Activists are guarding ships around the clock after 'sabotage' disabled other flotilla boats [David Poort/Al Jazeera]
Corfu, Greece. Activists planning on participating in an aid flotilla to the Gaza Strip are now guarding their ship around the clock after alleged sabotage disabled other boats in the planned convoy.
The Dutch-Italian ship Stefano Chiarini is waiting in a port on the Greek Island of Corfu for approval from the Greek government to begin the journey to Gaza.
The boat, set to host about 65 activists from several countries, is one of 10 flotilla ships currently gathering in Greek and Turkish waters with the aim of breaking the Israeli siege on the Gaza strip, the second attempt to reach the coastal enclave by sea in as many years.
The first "Freedom Flotilla" ended in disaster in May 2010, when Israeli commandos launched a predawn raid on the Mavi Marmara, a converted Turkish cruise ship, and killed nine passengers.
Due to alleged sabotage against this year's flotilla, activists on the Irish ship Saoirse have announced that repair work to their boat will not be ready in time to set sail.
Activists on both the Saoirse and the Scandinavian boat Juliano claim their boats fell victim to "hostile divers" who damaged their propeller shafts.
Co-ordinators on board the Saoirse said in a video posted on the ship's blog that they believe Israel was behind the damage, which they labelled an act of "terrorism".
"It's an absolute outrage that Israel talks about the flotilla as a provocation when they're willing to engage in this type of international terrorism," Fintan Lane, one of the co-ordinators, said.
The Saoirse's crew had taken the ship on a test run and refuelling trip on Monday when the engineer noticed that something was wrong.
When the crew returned, they discovered that the propeller shaft had been cut and "dangerously bent".
News of the alleged sabotage emerged on Thursday.
Though the Saoirse will not be able to join the flotilla, five of the Irish activists on board found space on the Stefano Chiarini.
In a bid to prevent further damage to the flotilla, activists on board the ship created a "security rota" and are now taking shifts to stand guard on their boat around the clock.
At any time, at least five people are patrolling the deck, with another in the galley, hoping to catch a perpetrator in the case of another attack.
Gerald Oberansmeier, an activist from Austria, spoke to Al Jazeera as he hung over the railing of the ship, shining his flash light on the water below.
"The water in the port is not very clear but we would see if bubbles come up. Bubbles are the main thing we're looking for. I might even jump in the water to scare them when I see bubbles," he joked.
The case of alleged sabotage occurred hundreds of kilometres away in a port near the Greek capital Athens, and in a port in Turkey, but Oberansmeier thinks it is not unlikely that the same could happen to the Dutch-Italian boat on Corfu.
"The goal of Israel is to prohibit these ships to set sail to Gaza. They are obviously willing to commit, what the Irish have said was an act of international terrorism, to prohibit this flotilla to set sai," he said.
"I think sabotage in which the lives of people are endangered is indeed an act of terrorism. The sabotage was done in a way that the ships could sink during their journey.
"We now have four people on deck - one on each side of the ship - and one person inside the galley to pick up on any suspicious noise. We're not paranoid.
"These acts of sabotage should make us cautious. Better to be cautious than sorry."
Early on Friday morning the "guards" on the ship rang the alarm bells when one of them heard a noise coming from under the 20 metre long vessel.
"For a brief moment we heard a knocking sound every 15 seconds, and we saw some disturbance in water next to boat," one activist said.
Immediately, the nearby coastguard vessels were notified and, after daylight broke, a diver was send down to check the hull for damage.
It turned out to be false alarm, but the incident shows how alert the activists are to prevent any kind of sabotage against their boat.
'Drill a hole'
"The coastguard is keeping a close eye on us," Chris Verweij, a Dutch activist on the boat, said while playing cards on the back of the ship.
"They are afraid that we would sneak out of this port without the necessary approval from the Greek authorities.
"But the captain of our ship, a Greek from Corfu, knows them and reassured them we won't be doing anything illegal. Now they are letting us be. They allow us to sleep on the ship and guard it at night.
"The damage that was done to the other ships shows the necessity of standing guard. We're not seeing ghosts here."
Looking over his cards, Verweij speculated over how hostile divers could go about doing damage to the boat.
"They could use other techniques than were used for sabotaging the other ships. They could easily drill a hole in the hull at the front of the ship," he said.
"Personally, I think now chances are very slim that they will do something against our boat, with people patrolling on deck and the coast guard 20 metres away from us."
The flotilla ships are still waiting for the Greek authorities to give them the green light for departure towards the Gaza Strip.
Organisers are locked in a bureaucratic battle with port authorities on Corfu, who claim that the activists of the Stefano Chiarini do not comply with regulations needed to undertake the voyage.
"It is very obvious that the Greek government is doing the bidding of Israel," Khaled Tuhraani, a leading activist, said at a briefing to the activists on Friday.