RedactedNarrative: we were first on scene, and observed 4 persons in the water, all wearing life jackets, and holding onto a blue and white pwc.  Ico hauled the 4 subjects onboard the 29wac patrol boat while cpl maintained the boats positioning in the 6-8 foot waves.    The 2 smallest and youngest children were displaying secondary signs of hypothermia, and the eldest daughter was displaying initial signs of hypothermia.  They advised they were in the water for approximately one hour prior to arrival of the ico boat.  All 4 were secured and warmed in the cabin.
  
  owner/operator advised he was operating his 4-seater pwc with 3 additional onboard, in the 6+ foot waves, eastbound to awaiting family at indiana dunes state park from burns ditch when the motor started to stall.  It stopped running approximately 1 mile offshore in front of bailly nipsco, porter county.  The pwc was taking on water as it sat extremely low in the water as the waves kept crashing onto it.  Unsuccessful attempts to start it caused operator to make his daughter call 911.  
  	 
  cpl inspected the craft and discovered that the port bilge plug was not fastened.  This would have caused the gradual taking on of water which would have flooded the engine compartment.  This would eventually cause failure and inoperability of the pwc engine.  operator could not recollect if he checked the plugs or not, nor did he outwardly show a real understanding of their purpose.  operator was issued wt for his pwc's expired mb registration, and released.
NameOfBodyOfWater: Lake Michigan
NearestCityTown: Portage