I am documenting by video and photographs the river Ythan near to where I live. On Friday I flew a 800 meter section from the sea up the Estuary at Newburgh about 8 to 10 miles East as the crow flies from Aberdeen airport at Dyce. There is one runway North to South direction, helicopters servicing the North Sea Platforms do approach Dyce from the East over Newburgh in good weather. Weather was good maximum flight height was 45 meters recorded, maximum distance from me was 400 meters within line of sight. The airport no fly zone outer limit was miles away, the flight was normal with no safety issues regarding people or property. I posted some photo's and video on social media and received some concerning responses regarding flying in controlled airspace. Basically, did I contact air traffic control and if not I would be reported to the CAA for putting helicopter traffic at risk. I was aware helicopters flew over the area and because of that set a height limit of 50 meters. Normal height limit is set to 120 meters in the app, I would hazard a guess the helicopter traffic flying overhead are at least 300 to 500 meters in height. I had good GPS signal, I'm not sure if the app would have limited my height down from 120m that distance from the airport as I did not check. I believe I fly responsively and was sure I was abiding by UK airspace laws / guidelines. However if any of the knowledgeable folks out there think otherwise let me know. As I was below 60 meters class A,C D or E airspace rules do not apply correct?