Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Henderson Island' has mentioned 'Tide' in the following places:
Occurrence Sentence Text Source
They found the island's only known drinkable water source xe2x80x93 a brackish spring on the north shore, exposed at half tide xe2x80x93 and ate fish, birds, eggs, crabs and peppergrass, but within a week they had largely exhausted the readily available food.
There is only one known potable water source, a brackish spring on the north shore exposed at half tide, rising from a crevice in flat rock, large surfaces of which compose the face of the beach.
The surrounding ocean tidal range is about one meter at spring tide.