The Red Sea or Red Stream?

Thanks for your question. I'm not sure which modern scholar you're reading that claims to know more than those that were actually at the Red Sea when it was crossed, but if they desire to believe the whole Egyptian Army drowned in 10" of marsh land so be it (Heb 11:29). That would be a pretty large miracle too! This said, we have to be careful of those that attempt to twist, turn, and torture the text of Scripture (cf. Rom 1:25).

Essentially, a miracle is by definition something that someone can't explain naturally. While God can make use of the wind, water, gravity and other means he is "yet free to work without, above, and against them, at his pleasure" (WCF 5.2). This can be described as "extraordinary providence." Louis Berkhof defines miracles as his extraordinary providence in which God "works immediately or without the mediation of second causes in their ordinary operation." According to Berkhof, this providence would include events in which God might use the forces of nature "in a way that was out of the ordinary to produce unexpected results."

God led Israel into an impossible situation (Exod 14:1-2); the Egyptians were on one side and the Red Sea on the other. There was no normal escape available. Then God the creator of all the seas (Gen 1:10; Psa 95:5; 146:6; Jonah 1:9; Acts 4:24; 14:15; Rev 14:7), divided the Red Sea. Israel crossed over it as by dry land and were delivered. The Egyptians attempted to follow Israel and died. God's parting of the Red Sea was a miracle (Exod 14:1-31).

Israel crossed the Red Sea as by dry land more than likely near the Gulf of Aqaba, probably down at its southern outlet. If we were to measure the Red Sea today, according to Smith's Bible Dictionary, we would discover that its average depth is from 2500 to 3500 feet, though in places it is as much as 6000 feet deep. Moreover, while the Bible does not tell us the actual depth of the water where the Red Sea was crossed by the Israelites, it was deep enough to be recognized some 40 years later as a miracle by a pagan later turned Christian - Rahab the harlot (Josh 2:10). Pagans would not have believed in the living God had this just been some stream!

How deep was it? Isaiah 51:10 states, "Was it not you who dried up the sea, the waters of the great deep, who made the depths of the sea a way for the redeemed to pass over?" Twice in one verse we observe the word "deep" referring to the sea Israel crossed. While the second Hebrew word translated as "depth" is maamaqqim and is translated as ''deep or depths," the first Hebrew word translated as "great deep" is tehom, meaning "deep, sea, or abyss." It is the same word used for the creation of the sea in Genesis 1:2 and for speaking about the flood of water that covered the entire world in the time of Noah (Gen 7:11). So, the Red Sea is rather deep.

The Red Sea crossing was a miracle. It is a historical event that numerous Bible authors have affirmed (Exod 14:21; Psa 66:6; 78:13; 106:9; 136:13; Isa 63:11; Acts 7:36; 1 Cor 10:1-2; Heb 11:29). Yes miracles do exist!

References:

Louis Berkhof, Systematic Theology, (Grand Rapids: Eerdmans, 1996), p. 176.