Next year, I will be cutting right through that corner.

Now that I'm back on the computer, I can see why the H16s were able to avoid Featherbank channel. You can stay West of the channel by staying West of the adjoining bank, ie. waypoint 25 32.0 N, 80 15.9 W. Then stay East of Pelican Bank, ie. waypoint 25 26.9 N 80 16.85 W and head for Midnight Pass. You just need to ask if there is a favored side to Midnight Pass or if you just go down the middle. You can download the chart at:
http://nauticalcharts.noaa.gov/mcd/Raster/Index.htmChart 11451 covers Biscayne Bay and you will need to download a a program (links on site) to read it. The Maptech software seems to work well. This stuff is not intended for navigation, but it appears to be quite good with the cursor giving the LAT/LON numbers. Much easier than using a divider on a physical chart.