This is what happened to the boats left in the Port Hinchinbrook Marina at Cardwell, when Cyclone Yasi hit the area back in February 2011
Boats that had been taken up some of the mangrove tributaries of the Hinchinbrook Channel, survived...In the Cairns port, boats that size are taken up the Cairns inlet, as far as possible, among the mangroves.
There have been several similar size boats moored in the Mulgrave river, here at Deeral for many years! When ever flooding or a Cyclone is expected, the boats are taken up into a mangrove creeks which runs in where the Mulgrave and the Russell rivers meet, these boats have never sustained any damage, either from flooding or Cyclones.
Frank.