A sea scooter rider was injured when his vehicle was involved in a collision with a boat off the Dorset coast.
Portland Coastguard received two emergency calls on Sunday afternoon after the crash in Studland Bay, Poole.
One of the watercraft riders was airlifted to Poole General Hospital, a second person onboard was unhurt. No-one on the trimaran was injured.
Police and the Marine Accident Investigation Branch are investigating.