Gaza’s Health Ministry said Monday 10 Palestinians were wounded by Israeli fire along the territory’s coast.
Thousands of Palestinians gathered on the beach as boats sailed nearby.
A Palestinian cameraman in a clearly-marked “Press” vest was shot in the leg.
Protesters set fire to tires on rafts.
Israel’s military said forces shot next to the vessels and at Palestinians on land who threw an explosive device and rolled burning tires at soldiers.
Monday’s demonstration led by Gaza’s Hamas rulers was, in part, to protest the blockade set by Israel and Egypt in 2007 after the militant Islamic group took over.
Hamas has led weekly border protests since March. Since then, 128 protesters have been killed by Israeli fire and one Israeli soldier was killed by a Gaza sniper.