While the threat of submarines has abated, the waterway is still a busy shipping route. A heavy barge will flatten head-on waves, but a large wake from an overtaking boat may twist a tug away from its barge, parting the cables that join them. Pass dredges at very slow speed on the side marked for safe passage with two black diamonds. Recently, at "Confusion Corner", where the ICW crosses Florida's St. Lucie River, a dredge was taking up most of the channel. Thankfully, I remembered the phrase "diamonds are a girl's best friend" from a boating course I took long ago. If in doubt, radio the dredge.