Rainwater obviously plays a role, but unseen water also matters.

The swash of waves succeeded it; unseen waters were slapping against shallow rocks.

It seemed he could hear the rush of unseen waters.

Somewhere under the earth, quite nearby, a murmur of unseen water could be heard.

The sound of something splashing into unseen water.

Then she climbed into the shaft leading down toward the unseen water rushing toward the inner wall.

They approached the two shapes cautiously, not knowing what they were looking at or whether more might be floating under water, unseen.

His cosmos was the barge, the dark, the unseen water, the presence of Zap 210.

His movements were sluggish, blunted by the unseen waters.

Silence spread in its wake till the unseen water had the single voice.