Hamas professes eteternal jihad until Israel's extinction, as do umpteen other Gazan groups. Israel is entitled to patrol the region with prejudice, at times extreme prejudice. The solution for Gazan fisherman is simple: change the regime, or get the regime to change. They voted for Hamas, after all.
Ya'alon okays administrative detention of Jewish extremist suspected in church arson (Haaretz)
from the article: Pro-Palestinian activists set sail to document plight of Gaza fisherman