The depth across the Bahama Banks is shallow. Mostly around 20 feet deep. When you get to the Northwest Channel and The Tongue of the Ocean (Yes, this is a real place.), The change is drastic. It is like falling off a huge underwater cliff in a matter of 50-100 yards. We left Chub Cay, with a depth of 10 feet, and were in 1,000+ feet in about two minutes. Because we left before dark, we had the Furuno on split screen. The right hand side of the screen is our radar, which helps us see the things we can't see in the dark. The left hand side is the depth. It gives you a visual look at the bottom. The first picture shows the dramatic drop off. The second picture shows the deepest reading we got before the depth meter was no longer able to read the depth because it was just too deep. Supposedly this is some of the world's best fishing ground, but we got skunked! No fish for dinner! Guess Brandon will need to come show us how it is done!!!