I wonder why No.6 did not try to escape the confines of the village by swimming to the far side of the estuary? He could have gained possession of an air tank worn by divers, well there were several sightings of "frogmen" in wet suits about the village during the parade of Dance of the Dead, and during the evacuation of the village at the time of Fall Out are but two occasions. And why not? The village administration permits water sports, water skiing and so forth, so why not underwater diving?
Then having gained a wet suit, air tank, No.6 could have swum to the far side of the estuary under water, un-observed and free from attack from the village guardian. After all we only see the village Guardian attack or pursue villagers on land or on the surface of the sea, not beneath the waves! Mmm that might have made for an intersting scene in itself.