Assertion: snorkel's tube | /r/CapableOf | extend behind the user's head
Facets:
value: upwardly
type: MANNER
Source sentences:
text: It has been discovered, according to the present invention, that if a mouthpiece is designed to fit into the user's mouth and contains within it at least one chamber which extends to at least one hollow breathing tube which is designed to conform to the shape of the side of the user's face and head and which hollow tube extends upwardly and backwardly behind the user's head and just above the user's ears.
text: A conventional snorkel has a mouthpiece which is cumbersome and a tube which extends beyond the user's head, to thereby permit the user to perform shallow dives in order to see beneath the surface of the water.