Unknown Jet flying low on the Cooley Pennisula

I was just on my way home from college today on the bus and I saw a small jet engine/ turbo prop aircraft flying awfully low along the shore. It looked like the Avro or the ATR props but I couldn't tell 100%. Looked on FlightRadar24 and PlaneFinder but it didn't yield any results. The livery was darkish so I'm thinking it could've been the Aer Corp but I don't know. Can any tell me who it was and why was it flying so low?

My dad suggested to me that it could be doing an aeriel photography but I was thinking who would shell out huge money to charter a plane that size to take photographs. My best guess it that it was a training flight maybe?