The Dead Sea, the largest body of water in the Promised Land, has hidden references in the Bible. It is referred to through phrases such as the "salt sea" (Genesis 14:3, Numbers 34:3, 12, Deuteronomy 3:17, Joshua 3:16, etc.) and the "sea of the plain" (Deuteronomy 3:17, Joshua 12:3).
The Euphrates River is recorded, by name, twenty-one times in Scripture. It is, however, twice called "the river" (Numbers 22:5, Deuteronomy 11:24). It is also generically referenced by the phrases "the great river" (Genesis 15:18, Deuteronomy 1:7, Joshua 1:4, Revelation 9:14, 16:12) along with "waters of the river" (Isaiah 8:7).
The Mediterranean Sea is not mentioned by name in Scripture. It is, however, generically called "the sea" (Joshua 16:8), "the great sea" (Numbers 34:6) and "the uttermost (utmost) sea" (Deuteronomy 11:24, 34:2). It is additionally referenced as "the sea of the Philistines" (Exodus 23:31) and Ezra the prophet called it "the sea of Joppa" (Ezra 3:7).
The Nile River is yet another great pathway of water not mentioned by name but hidden in the Bible. It is generically called "the river" in several places (Genesis 41:1, Exodus 1:22, 4:9, 7:17, 8:3, 17:5). Another possible reference to the Nile may be the phrase "river of Egypt" in Genesis 15:18.
The Tigris River, though the last of our hidden waterways not directly named in the KJV Bible, is referenced by its Hebrew name Hiddekel in Genesis 2:14. Daniel's use of the phrase "the great river" is also referring to the mighty waters of the Tigris (Daniel 10:4).