Skipper Harmon is referring to a stretch of shoaling at the eastern end of the Okeechobee Waterway where we have had a Navigation Alert posted since May of 2013, (see http://cruisersnet.net/?p=113451). Again, our advice, and that of Skipper Harmon, is to ignore the magenta line and follow the markers.
The problem stretch near markers 17 and 17A claimed another boater. I recently completed the Okeechobee Waterway and found the charts make this area very confusing and, the small can marker 17A is hard to see. The charts depict a dredged channel and the magenta line indicates you can pass west of the green marker 17. If you follow this route (magenta line) you will find very shallow water. When I passed the area all east bound traffic was leaving the green markers 17A and 17 to the starboard, west bound to the port. If you are meeting traffic, slowing down will allow everyone to pass 17 safely.