What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) Crew change from MP265 to MP277, N518RL. Picked up at MP265 to a hover gauge checks 85% torque rotor RPM and turbine in the green. N1 91.5, tot 600 deg. I armed the floats and departed MP265. Midway into the flight pilot noticed the low RPM light and horn. Pilot checked to make sure the throttle was full open, pilot simultaneously lower the collective. Throttle was full open and the engine gauge was in the green, but rotor RPM was still decaying. Pilots altitude was 400 ft, pilot lowered the collective and reduced speed to 60 knots. Pilot warned passenger he was going to make an emergency landing. Pilot contacted the main base to give his location, and landed the aircaft in the water. No injuries, to the passengers or the pilot.
As the FAA filed it
(-23) CREW CHANGE FROM MP265 TO MP277, N518RL. PICKED UP AT MP265 TO A HOVER GAUGE CHECKS 85% TORQUE ROTOR RPM AND TURBINE IN THE GREEN. N1 91.5, TOT 600 DEG. I ARMED THE FLOATS AND DEPARTED MP265. MIDWAY INTO THE FLIGHT PILOT NOTICED THE LOW RPM LIGHT AND HORN. PILOT CHECKED TO MAKE SURE THE THROTTLE WAS FULL OPEN, PILOT SIMULTANEOUSLY LOWER THE COLLECTIVE. THROTTLE WAS FULL OPEN AND THE ENGINE GAUGE WAS IN THE GREEN, BUT ROTOR RPM WAS STILL DECAYING. PILOTS ALTITUDE WAS 400 FT, PILOT LOWERED THE COLLECTIVE AND REDUCED SPEED TO 60 KNOTS. PILOT WARNED PASSENGER HE WAS GOING TO MAKE AN EMERGENCY LANDING. PILOT CONTACTED THE MAIN BASE TO GIVE HIS LOCATION, AND LANDED THE AIRCAFT IN THE WATER. NO INJURIES, TO THE PASSENGERS OR THE PILOT.