The body of water that separates northeastern Africa from the Arabian Peninsula; it includes the two arms known as the Gulf of Suez and the Gulf of ʽAqaba. The Red Sea, as the term is now used, measures some 2,250 km (1,400 mi) in length, has a maximum width of about 354 km (220 mi) and an average depth of approximately 610 m (2,000 ft). It is part of the great geologic fault known as the Rift Valley. Because of a fast rate of evaporation, the waters of this sea are quite salty. Strong winds, rapid changes in wind direction, and the presence of large reefs make it hazardous for boats to navigate the Red Sea. Along the eastern coast there are high mountain ranges, whereas rocky tablelands and low hills occupy the western coast.

There is good reason for understanding that the original-language expressions rendered “Red Sea” apply to the Red Sea in general or to either one of its northern arms. (Ex 10:19; 13:18; Nu 33:10, 11; Jg 11:16; Ac 7:36) It was the waters of the Red Sea that Jehovah miraculously divided to let the Israelites pass through on dry land, but he drowned Pharaoh and his military forces who came in pursuit. (Ex 14:21–15:22; De 11:4; Jos 2:10; 4:23; 24:6; Ne 9:9; Ps 106:7, 9, 22; 136:13, 15) The Biblical passages relating this incident use the Hebrew expression yam (sea) or yam-suphʹ (sea of reeds or rushes). On the basis of the literal meaning of yam-suphʹ, certain scholars have argued that the Israelites crossed a mere swampy place, such as the Bitter Lakes region, and not the Red Sea (principally the western arm, the Gulf of Suez, where others believe the crossing likely occurred). However, it should be noted that the waters were sufficient to cover Pharaoh’s military forces. (Ex 14:28, 29) This would have been impossible in a mere swamp. Also, Acts 7:36 and Hebrews 11:29 rule out a mere swampy place, for these texts mention the same incident and use the Greek expression e·ry·thraʹ thaʹlas·sa, meaning “Red Sea.” (See EXODUS.) The historian Herodotus (fifth century B.C.E.) used the same Greek expression to refer, not to a swamp or an insignificant body of water, but to “the Indian Ocean, in which the Red Sea” is located.​—A Greek-English Lexicon, by H. G. Liddell and R. Scott, revised by H. Jones, Oxford, 1968, p. 693; see PIHAHIROTH.

In a pronouncement of doom for Edom, the outcry resulting from Edom’s calamity is described as being heard at the Red Sea. (Jer 49:21) This is understandable, since Edomite territory in its southern extremity bordered on the Red Sea (1Ki 9:26), that is, the sea’s northeastern arm, the Gulf of ʽAqaba. Israel’s boundary also extended to this point.​—Ex 23:31.