2010 zr409 non cat ...antifreeze in heater?

[Skihart]

Hi
I bought a 2010 200team this year and love the boat. It has the zr409 non cat motor. It's almost time to think about winterization and have been going over the procedures but can't seem to find out if the heater has antifreeze in it, or just runs water. I assume it's antifreeze with closed cooling system but the manual doesn't seem to specify? if it's antifreeze then I don't need to worry about it correct?
thanks

[Quinner]

Closed or open loop the heater lines will be coming off the manifold and water pump, so in a closed loop that means heater will be on the closed side and running anti-freeze, no drain required.