The wreck is lying at the bottom of the sea.

沉船躺在海底。

《牛津词典》

The ship was buried, beyond retrieval, at the bottom of the sea.

船已葬身海底，无法打捞。

《牛津词典》

Sea cucumbers are strange animals living at the bottom of the sea.

海参是生活在海底的奇怪动物。

youdao

The area then was at the bottom of an ancient sea.

VOA: special.2009.01.07

Whichever comes out on top, though, it is clear that astronomers believe there is treasure to be found at the bottom of the sea.

ECONOMIST: Neutrino astronomy: Deep and meaningful | The

The road dips a precipitous path along the ridge from where the deep geological gash of the Great Rift Valley cascades downwards to meet its bottom at the Dead Sea, 400m below sea level.

BBC: Travelling the slow route to Petra

This was quite easy, because the sand at the bottom of the hole was very soft and fine and dry, like sea-sand.

NPR: Excerpt: 'Five Children and It'