CORRECT CRAFT super air 230 2018 Owner's Manual page 203

Boat Systems
The heater system has a heating core, ducts, diffusers and a high-
speed fan to deliver heat to the cockpit and windshield. The duct
diffuser at the windshield can be closed and rotated to direct air
flow. The floor ducts can also be closed to control air flow. The aft
duct and diffuser can be pulled out of its socket to direct flow in
other locations of the cockpit. The heating unit is located under
the driver's dash pod.
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