Beech 1900
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 5
Situational Awareness
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
General None Reported / Taken
Procedure; Human Factors
Aircraft X inbound to land ZZZ; level at 8;000 ft. I instructed Aircraft X to pilot discretion maintain 2;000 ft. Between the 8;000 ft. and 2;000 ft. MVA there is a 2 mile wide section of 6;000 ft. MVA. Aircraft X descended very fast and was at 3;400 ft. on the border of the 6;000 ft. MVA leading into the 2;000 ft. MVA. The aircraft was over open water and alert given. One change could be to accurately display MVA vs actual Terrain. The area Aircraft X descended in is directly over open water and was no danger to the aircraft; 6;000 ft. MVA is not needed in this location. I expected the pilot to not descend rapidly; from here on; I will treat 'PD' descents with more positive control and not let this event happen again.
TRACON Controller reported an aircraft descended faster than the Controller anticipatedresulting in a MVA violation.