MANILA, Philippines — A flotilla of about 100 mostly small fishing boats led by Filipino activists sailed Wednesday to a disputed shoal in the South China Sea, where Beijing’s coast guard and suspected militia ships have used powerful water cannons to ward off what they regard as intruders. [time-brightcove not-tgx=”true”] The Philippine coast guard and navy deployed one patrol ship each to keep watch from a distance on the activists and fishermen, who set off on wooden boats with bamboo outriggers to assert Manila’s sovereignty over the Scarborough Shoal.