{Teak surfing}

"Teak surfing" is a new water "sport" where swimmers hanging on to a powerboat’s swim platform (often made of teak) get towed through the water. In one variation, the "surfer" will let go and body surf on the stern wake. This is usually done without a life jacket because jackets can be uncomfortable.

In addition to the very obvious danger of swimmers being near moving propellers, there is a less obvious danger of carbon monoxide poisoning. A moving boat can pull a suction behind it which traps exhaust fumes behind the boat.

Carbon monoxide (CO) itself is tasteless and odorless. The major symptoms of CO poisoning are headaches, dizziness, nausea, seizures, and sleepiness, which inevitably lead to unconsciousness and death if the victim is not removed from its source to fresh air. The symptoms can often be mistaken for seasickness or flu. Many victims who survive have permanent brain damage. Anyone in the water without a PFD who is rendered unconscious will drown immediately.

CO poisoning is not restricted to swimmers behind a boat. It can happen whenever air currents pull the exhaust back into the cockpit or cabin of the boat or below decks when there is a faulty exhaust system.