Ba-32 what hidden and potentially deadly danger exists when teak surfing or platform dragging

It is that "carbon Monoxide can overcome participants".

Teak Surfing or Platform Dragging is clutching any part of the outside of the transom of a vessel for any measure of time while a power-driven vessel is in progress or the motor is idling. The vessel may emit an amount of carbon monoxide which is highly risky for the participants and can cause brain damage and in extreme cases death.