I’m pretty well-versed in the Bible myself, having spent some time in a private Christian school with daily Bible study, I know much of it by heart and off the top of my head. Regarding this particular matter, though, I don’t recall anything specifically stating that the seabed was one thing or the other, just that they were able to pass through. Please correct me if I’m wrong. My recollection is pretty good but not always complete or perfect.
Looking at that video of the artifacts, they would have been lying there for how many thousands of years? They’re barely covered with silt. I’d say the underlying seabed was not exactly a mucky quagmire as a result.
the video i linked to shows the floor- no stones- sand-
Why are you crying out to Me? The time for pleading and prayer was over. The time for action had arrived. Tell the Israelites to move on (14:15). In spite of Israel’s unbelief, God commanded: Raise your staff and stretch out your hand over the Sea of Reeds to divide the water so that the Israelites can go through on dry ground (14:16).