(Map 12:Y2–3). A large, heart‐shaped expanse of water, 20 km (12.5 mi) long by 11km (7 mi) wide at its maximum points. It forms a deep basin surrounded by mountains on both sides and a narrow, shoreline plain where several important cities and towns are located. This pattern is broken only at the northwestern corner, where this strip opens out into the plain of Gennesar, the fertility of which was extolled by Josephus (War 3.516–21). The lake surface itself is ca. 210 m (700 ft) below sea level, thus forming a large basin for the waters of the Jordan River. According to Josephus and Pliny its original name was the Lake of Gennesaret, although both authors are aware that it was also called the Lake of Tiberias (Josephus) or the Lake of Tarichaeae (Pliny), after two of the more important settlements on its shores in Roman times.
The gospels of Matthew (eleven times) and Mark (seven times) call it the Sea of Galilee, a designation also found in John 6 and 21. This may reflect the Hebrew (yam), which can mean either a freshwater lake or the sea properly understood. It has been suggested, however, that Mark's usage (followed by Matthew) has a more symbolic significance in terms of Jesus' control of the forces of evil that are associated with the deep (Job 38.8–11; Ps. 107.23–25, 28–29). Luke reserves the word “sea” for the Mediterranean and always speaks of the “lake of Gennesaret” (5.1, 2) or “the lake” (8.22–23, 33) when referring to the Sea of Galilee. The significance of this usage is that it suggests that Luke, although presumably not a native of Palestine, was able to project himself into that context and accurately reflect local usage in differentiating between sea and lake.
The lake provided a natural boundary between Jewish Galilee and the largely gentile territories of Gaulanitis and the Decapolis directly across. Despite differences of religious affiliation among the population on either side of the lake, archaeological evidence suggests a real continuity in terms of life‐styles, trading, and other relations. The Gospels also testify to this frequent movement, even when it is not always possible to detect accurately the points of embarkation and arrival (see Mark 6.45, 63; 8.10; John 6.22–24). Josephus too mentions fleets of boats on the lake, thus suggesting a busy and thriving subregion within Galilee and linking it with the larger region.
In addition, the lake was a natural resource for Galilee because of the fish industry. Strabo, Josephus, and Pliny, as well as the Gospels, all mention the plentiful supply of fish in the lake. Both Bethsaida and Tarichaeae are generally believed to have derived their names from the fish industry; the latter is most probably the Greek name for Magdala and is derived from the Greek term for preservation. Salting of fish, which made their export possible on a much wider scale, was, we know, a technical skill that was developed during the Hellenistic age. It is likely, therefore, that there was a genuine expansion of this industry in Palestine also. Josephus mentions (War 3.8.520) one type of fish, the coracin belonging to the eel family, which was also found in the Nile, suggesting perhaps that the early Ptolemaic rulers had expanded the fish industry to Galilee as a commercial enterprise. In this regard it is worth noting that James and John, the sons of Zebedee, would appear to have abandoned a thriving business, when they left their father and his hired servants to follow the call of Jesus (Mark 1.16–20).