According to Genesis, pitch was used to make Noah’s Ark watertight.
Genesis 6:14 instructs Noah to build the Ark from gopher wood and to cover it inside and outside with pitch. Pitch is a waterproofing substance traditionally associated with bitumen, tar-like material, or another sealant. The text’s practical detail explains how the wooden vessel was intended to resist flooding.
Translations vary in how they render the Hebrew term, so readers may encounter “pitch,” “bitumen,” or a related waterproofing word. The canonical short answer is pitch because that is the standard English wording in many Bible translations. This detail is distinct from the Ark’s wood: gopher wood describes the construction material, while pitch describes the waterproof coating.