The documentary suggests that the Israelites didn't cross the Red Sea, instead they crossed the "reed sea" - more like a big marshy/reedy lake. This is unlikely for the following reasons:
1. "Yam-suph" means "sea of reeds". The documentary uses this to suggest that the Israelites crossed a reedy lake. What they omitted, or didn't know, was that the exact same term, "yam-suph", was used for the actual Red Sea constantly throughout the bible (Jeremiah 49:21, Exodus 23: 30, Acts 17: 36, just to name a few). All of these scriptures are undeniably referring to the Red Sea, yet they all use the term "yam-suph" (before translation).
2. King Solomon later built a fleet of ships on the shore of "yam-suph" (1 Kings 9: 26).
This was evidently referring to the red sea because it adds "near Elath...in the land of Edom" which was a port on the coast of the Red Sea. Besides, a lake would be a very strange place to build a fleet of ships.
3. The next day the Israelites saw dead Egyptians "washed up on the seashore".
4. The size of the body of water made it near impossible for it to be a lake. A) Pharoah's entire military force went "down into the seabed". We're talking possibly hundreds of thousands of men that fit at one time. They were all "swallowed up", not a single soldier, chariot or horse survived. Evidently, the body of water must have been massive both in size and depth. It couldn't have been a reedy lake that could be waded in. B) This is the main one. The book of Numbers details a journey the Israelites took that saw them start at yam-suph and travel for many days before ending with them camping at yam-suph. How could the Israelites be by a lake, travel through several cities over several days, and still be by the lake? I only see two possibilities. Either it was a gargantuan lake, or it was exactly as the bible says - they were moving along the coast of the Red Sea. The only body of water big enough for the Isrselites to have travelled for so long and still be by the coast, was the Red Sea.
I'm not anti-science by any means, and I recognise that natural phenomena could be used or perceived as a miracle. But that only applies when it doesn't directly conflict with what the bible says. This documentary attempts to find a more natural and understandable explanation for something the bible says took spectacular, divine intervention.
It's the equivalent of trying to find a natural explanation for how Santa could possibly visit every home on Earth on the same night, December 25th.
You either believe and put faith in the bible and God's ability to perform miracles to save his people, or you don't. I don't see the logic behind taking something the bible explicitly says took divine intervention, and confining it to the laws of nature.