At 8:25 PM Fire/EMS units on the westside were dispatched for a reported "boat overturned with persons in the water" on the Potomac River near green buoy #45. Tenth District Volunteer Marine Division and surrounding marine assets responded to Sweden Point Marina and where "Command" was established by BC7B (Gimmel) launching Boat #8 and Boat #7. Boat #20 responded from NDW along with Boat #4 to assist. Boat #20 and Boat #8 arrived in minutes locating the sunken vessel and three persons in the 64 degree water. 2 rescue swimmers from Boat #8 entered the water to assist in the recovery. All three persons were successfully placed onboard Boat #8, they returned to Sweden Point for medical evaluation by PA8 and A79. One subject refused treatment, two subjects transported to local hospital for cardiac and cold exposure. Tow Boat US arrived, secured boat to the shore, DNR Police on scene, Coast Guard notified, Command terminated, great job by all on scene. 31 Fire/EMS personnel responded on this incident