Israel may be shutting down smugglers' tunnels between Egypt and the Gaza Strip, but Palestinian militants still have options for getting weapons into the occupied territories, including the sea.

"As long as it will be hard for them to do it via the tunnels, it might be that they will go back and do it via the [sea]," said Israeli Rear Adm. David Laurie, head of naval operations.

Laurie has reason to be concerned. In the last few years Israel has intercepted a number of ships carrying arms, including the Karine A (search), which was carrying 80 tons of weapons —enough to alter the balance of military power in the occupied territories.

Because of this threat, Israeli patrol boats keep constant vigil on the Mediterranean. But Palestinian fishermen are caught in the middle.

"We are scared of the Israeli Navy Patrol boats. If we get 10 kilometers away, we get worried that they might open fire on us," said Muhammed Abu Hassira.

The fishermen are restricted to a five-by-eight mile section of water that keeps them away from Egypt, Israel and Jewish settlements on the coastline of the Gaza Strip. Abu Hassira said the income for his crew has dwindled to about $15 a week.

The fishermen are trapped between their economic needs and Israel's security needs.

Click here to watch a complete report by Fox News' Mike Tobin.