I have been through the Indian Cay channel many times. I draw 4 feet, and my 2000 Yachtsman's Guide to the Bahamas (newest I have at home) says the depth is 5 ft low water, rocky bottom. Add 2.5 ft for hw and you have a good margin for error. The problem is that the water is sooo clear that it looks like it's about 2 ft deep! So go slow. The rocky part is to the left off Indian Cay Rock, and only goes for about the first mile, so even if the pile markers are missing (they usually are) you are starting from a known point and a gps waypoint will keep you in the good water. From there on everything is sand bottom which always worries me less. Baracuda Shoal was all sand last time I looked.
Going back is a little harder unless you preserve your gps fix off Baracuda Shoal so you know where to start going SW. Then at least you can see the pole for the light and you can avoid the rocks.
For this reason last year I decided to go home (West) from Mangrove Cay via Memory Rock, and on to Lake Worth Inlet. I had never taken this route, probably because it was pre-gps for me, and that little rock could be hard to find by dead reckoning. The 2000 Guide says I should have gone 2-2.5 mi SE of the light for the best water. I went about 1/2 mi south and had no trouble. The water was so clear I slowed for a white sand patch which turned out to have 10 ft of water on it. The only problem with this route is that there is no fuel between the USA and the marina at Spanish Cay, Abaco, or to Green Turtle Cay. Both of these are ports of entry for Bahamas Customs ($300, cash only).
I had planned on going into the marina at Settlement Point Grand Bahama which I had not seen in 10 years or so, but the Admiral said she would rather anchor out off Mangrove Cay instead. I have heard the marina's land development has gone on hold due to the economy. I believe the marina is ok.
You must have good light for these passages. Travel between 10am - 4 pm, wear polarized dark glasses. Once you are on the Little Bahama Bank it is a piece of cake, all sand no rocks.