"Fire, fire, fire," Lt. Yoni yells into the handheld radio. Seconds later the Typhoon cannon on the Shaldag patrol boat lets loose a volley of shells toward an open area on the Gaza coast. "There are indications that terrorists fire rockets from that area to Ashkelon and Ashdod," explained Yoni, commander of the 25-meter-long Shaldag-class Fast Patrol Boat, which can reach a cruising speed of up to 45 knots. Before the cannon fire, Yoni and his men scanned the coast with an advanced thermal camera to ensure that no IDF soldiers were in range. Suddenly, as the camera focuses on a hotel under construction, one of the sailors says: "Wait a second, there is something there." The camera zooms on what turns out to be a pack of wild dogs. It is before dawn on Friday, the 14th day of Operation Cast Lead, and we are sailing off the Gaza coast, looking for Hamas targets. The vessel passes the INS Tarshish, a Sa'ar 4.5-class missile boat. The moon is full and the skies are clear, a beautiful night, one of the sailors remarks, for a cruise in the Mediterranean Sea. Since the beginning of Operation Cast Lead, most of the credit for the attacks on the Hamas infrastructure has been given to the air force, which has conducted hundreds of sorties. The navy, however, has been operating off Gaza since the first day of the operation, December 27, using precise munitions, and has attacked some 200 targets scattered across the Strip. The ships receive their targets from the navy's Operations Center. Inside the center, officers sit around a table looking at a wall full of screens of different shapes and sizes. One screen shows a radar view of the sea, another troops in Gaza and the launching of rockets into Israel. One screen sits prominently in the middle of the wall and on it the officers watch Al-Jazeera report live from the Strip. "We protect Israel's longest border - the sea," says Lt.-Cmdr. Zur, deputy commander of the navy's fast-patrol boat division. "This also includes the fishing waters off the Gaza coast, where we work to prevent terrorist infiltrations into Israel." The navy has two advantages over the IAF when it comes to hitting a target in the Gaza Strip. First, its weapons are not limited by the weather; a ship can hit its targets even when there is heavy fog and clouds. The second advantage is the precise munitions that the ships carry. In some cases, the navy has succeeded in firing Typhoon shells through a window and into a building where Hamas gunmen were spotted. "We can get to places where no one else can get," a senior navy officer said. "We have weapons with great accuracy as well as the ability to stay at sea for an extended period of time." The navy's mission in Operation Cast Lead has been to blockade the Gaza Strip, to stop the smuggling of weapons and to prevent Hamas from carrying out terrorist attacks against Israel from the sea. The navy maintains a fairly large permanent presence off the Gaza coast. Several other Israel Navy vessels sail in the area, including Sa'ar 4.5-class boats that hunt down Hamas terrorist cells and provide support for ground operations. In one mission, ships fired at Hamas gunmen who had laid ambushes for paratroopers deployed on a Gaza beach. "The navy joined the military operation on its first day," the senior officer says. "Since then, we have attacked [rocket] launchers and bunkers, and have backed up ground forces operating in the Strip, helping them open routes and clear out suspicious areas and houses from which gunmen have opened fire." There has been an unprecedented level of cooperation between naval and ground forces, he says. "There is direct contact between battalion commanders and naval commanders." The navy has also hit Palestinian police boats, and according to the officer, the "Hamas Navy" has been dealt a severe blow. The officer said there had been attempts to fire at Israel Navy ships, mostly with light arms and anti-tank missiles. Ships like Yoni's, anchored off Gaza, hunt for terrorists and rocket launching cells. On Monday, 10 Hamas terrorists were killed by naval forces. There have also been attempts by Palestinian boats to approach naval vessels, and the IDF suspects that they are trying to perpetrate an attack similar to that on the USS Cole in Yemen in October 2000, when a small boat rammed into the guided missile destroyer, killing 17 sailors. There have also been attempts to smuggle arms via the sea into the Strip. "All the time, there are attempts to approach us - they are dying to hurt us," said the officer. "There is now a naval blockade, so anyone at sea is considered suspicious." Some of the sailors live in the South. Felipe, who emigrated from Argentina with his family 12 years ago, lives in Beersheba, in range of Hamas's Grad rockets. "What is happening at home is a little frightening," says Felipe. "On the other hand, I'm happy to be here defending my home, because that's the reason I joined the navy."