The blockade is a collective punishment over an occupied population by the occupier force, so it is illegal. Israel doesn't have any right to impose it, so it is not only acceptable, but also morally necessary to break it. If Israel reacts violently to such a peaceful and righteous move, it should be tried and sentenced for it. Just lift the blockade, and flotillas will stop.
Policeman killed by blast in Bahrain village, interior ministry (Reuters)
from the article: The chief of staff threatens