Which ancient text tells of Utnapishtim surviving a flood in a large boat?

The Epic of Gilgamesh tells of Utnapishtim surviving a flood in a large boat.

In the flood narrative on Tablet XI, the god Ea warns Utnapishtim to build a boat and preserve living beings, family, craftsmen, and animals. Utnapishtim later releases birds to determine whether the waters have receded. The episode is one of the most important ancient parallels to the story of Noah.

The Epic of Gilgamesh is a Mesopotamian literary work preserved in several versions, with the best-known surviving form written in Akkadian cuneiform. Its flood account shares motifs with the earlier Atrahasis tradition, including divine warning, a vessel, a catastrophic flood, and the testing of land conditions with birds.

The two stories are not identical. They use different names, divine systems, narrative purposes, and details. The comparison is historically important because it places the Noah story within a wider ancient Near Eastern flood-literature tradition.