יָם yam "sea" in the Canaanite cultural background, which sometimes shows through in the Bible Yam was a god, an opponent of Ba`al ("the lord"). In any case to the landlocked Hebrews the sea with its movement and hidden depths was frightening and mysterious. In Amos the word occurs:

• once in the expression "from sea to sea" (Am 8:12) = "everywhere"
• twice in the hymn fragments in the expression "waters of the sea" (Am 5:8 & 9:6)
• and at 9:3 as part of a catalog of places where even if the foolish Israelites believe God is absent, they will discover that hiding from him is useless.