On 07/22/2023, Vessel 1 (V1) was in operation on Pactola Reservoir in Pennington County, South Dakota.  V1 was occupied with an operator (O1), and three passengers (P1, P2, P3). V1 is a 2003 Mastercraft equipped with an inboard drive. 

At approximately 10:30 AM,  P1 was seated on top of the transom with feet resting on the swim platform. P2 was riding a boogie board style device near the rear of V1. P2 was wearing a PFD. Half of the boogie board was in the water while the other half was resting on the swim platform. 

P1 was holding onto the boogie board as P2 was positioned on the boogie board. O1 operated V1 at low speeds for approximately five to ten minutes while P2 was on the boogie board near the swim platform. 

O1 stopped V1 and P2 got off the boogie board and entered into V1. P2 started complaining of stomach aches and was feeling unwell. 

P3 recognized something wasn't right with P2 and called emergency services at approximately 10:45 AM.  V1 relocated to the south marina to meet emergency services. At approximately 11:14 AM, medical emergency services arrived and had P2 lay down. A short time after P2 had laid down, P2 went unconscious. Medical aid was given and P2 regained consciousness. P2 was transported to Monument Hospital by medical helicopter. Medical professionals determined P2 suffered carbon monoxide poisoning from riding near the rear of V1 for an extended period of time.

PACTOLA RESERVIOR
RAPID CITY                    