While the rest of the Gaza Strip is deep in slumber, Fathi Sayadi, 30, and his brother, Hatem, 26, steal away under the cover of darkness and into neighbouring Egyptian waters.

Using small, dinghy-style boats purchased especially for their covert missions, the Sayadis slip across the border with Egypt, returning to the Gaza Strip with their contraband just before dawn.

But, as Israel often claims, they are not using their boats to smuggle weapons into the Hamas-run territory. They are instead among a growing number of impoverished fishermen crossing the Gaza-Egypt maritime border to buy fresh fish from the country’s nearby port cities and Egyptian fishermen out at sea.

The Sayadi brothers say the Israeli navy caught them as they crossed back into Gaza from Egypt for the fourth time on January 15 and questioned them about their trip, something the Israeli military confirmed. But they are unfazed.

“We will go again whenever the weather gets better,” Fathi Sayadi said, as dark thunderclouds rolled in off of Gaza’s coast. “It is better to go at night, but it depends on when we can afford the fuel. We buy whatever we can from the Egyptians, even if it’s just the leftover fish.”

Israel and Egypt sealed their borders with the Palestinian coastal enclave after Hamas seized power in Gaza in June 2007. The ensuing economic blockade, which bans all commercial imports and exports to and from the territory, also prohibits Gaza’s 3,500 fishermen from trawling beyond 5.5km, down from the 37km limit stipulated by the Oslo Accords.

Seventy per cent of Gaza’s annual sardine catch, which is about 1,800 metric tonnes, is found outside the Israeli-imposed fishing zone, says the International Committee of the Red Cross.

The other side of the barrier, patrolled heavily by Israeli warships, is also home to at least a dozen other varieties of fish and seafood, including octopus, shrimp, tuna and crab.

The industry makes up between two per cent and four per cent of the Palestinian gross domestic product, according to the United Nations. Palestinian GDP was approximately US$4.5 billion (Dh16.5bn) in 2009, according to the Palestinian Bureau of Central Statistics.

“The fishermen do not feel at all safe at sea,” said Stephane Beytrison, the head of the Red Cross field office here. “Not all of them have GPS [global positioning systems], and in some cases even that doesn’t make a difference. They can be shot when they are three miles out or just two, they never know.”

The Sayadi brothers and several other fishermen who have also crossed the border but wished to remain anonymous say they stay close to shore when they make the 90km journey to the Egyptian seaside town of Al Arish. The Sayadis got the idea from their father, they say, who was a fisherman for 40 years and would dip his boat into Egyptian waters to visit friends. Now, the fishermen say, they do it out of necessity.

“If our sea were open, our fish would be better,” Fathi Sayadi said. “But in Egypt, they have access to all the things we don’t. I have four children and my brother has two. What can we do?”

The fishermen buy the Egyptian fish for what they say are good prices in Egyptian pounds, then sellit at a higher price on the Gaza market. They claim to make about 500 shekels (Dh492) in profit with each trip, which goes towards fuel and paying the salaries of workers they hire to transport the fish to market.

In comparison, the average monthly salary of a Gaza fisherman is just 250 shekels, down from 1,300 shekels before the blockade, according to the Red Cross.

“Isn’t it ridiculous that fishermen are required to buy fish from other fishermen, in another country?” said Abu Nidal, an elderly fisherman whom many of the Gaza City seamen consider to be their de-facto leader. “We used to export our fish. But now we import – and we barely do even that.”

The head of the fishing department at Gaza’s ministry of agriculture, who asked to be referred to as Abu Yusuf because of his affiliation with the Fatah-led government in Ramallah, estimates between 15 per cent and 20 per cent of the fish in Gaza’s market comes from Egypt, whether through the tunnels or from fishermen making the risky trip across the border.

A further five per cent is imported from Israel, and the market works against other local fishermen as a result, officials here say. According to Ahmed Araf, a merchant at Gaza City’s fish market, 300 grams of denise, a local variety of whitefish, used to sell for 100 shekels. Now, with more fish coming from Egypt, the price has dropped to 40 shekels.

Abu Yusuf said the government in Ramallah sends cash provisions to Gaza fishermen to help them deal with the losses. But it is not enough to keep them from their daring night-time jaunts into Egypt, the fishermen say.

“If they don’t want us to go to Egypt, then open the sea,” Abu Nidal said. “End the siege and just let us fish, so that we can live.”