Moses and Exodus 31

The Israelites had left Egypt behind and were camped at a place "by the sea." Geographically speaking, there were interesting aspects about this location which made it a precarious and curious place for them to be. Could this be why Pharoah thought he could catch and capture the Israelites (besides the fact that he had Egyptian chariots and they did not)? What was so special about the Egyptian chariots? And what about those pillars, one of fire and one a cloud, which went before the Israelites? We also find them mentioned later in Isaiah and in Revelation!