Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Sea
Flight Crew Last 90 Days 120; Flight Crew Total 11200; Flight Crew Type 5000
Distraction; Confusion; Human-Machine Interface; Workload
Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Other / Unknown
Flight Crew Took Evasive Action
Human Factors
Flying south of the Class C airspace; and under Class B airspace at about 1200 feet I got an ADS-B collision alert for an aircraft approaching from a 7 o'clock position. I adjusted course to increase separation. The other aircraft appeared to adjust its course to intercept mine as its altitude decreased towards mine. I adjusted course again to make mine almost 90 degrees to my original 270 heading. The aircraft's course depiction followed and appeared to be closing. I made a rapid descending 180 degree turn to visually locate the airplane. I immediately located the Cessna who did appear to be following me. After my turn and descent avoided risk of collision; the aircraft then turned north and entered Class C airspace. I noted my position was very close to the Class C boundary and immediately turned back away to avoid entering the airspace. I did not enter Class C but was uncomfortably close. As I proceeded to get further separation and continue in a generally westerly direction I noted the airplane turned again and appeared on a parallel path but at a higher altitude.  As it was faster it eventually passed heading towards another Class D airspace. This type of event has happened before; but rarely; when other aircraft seem to interested in the slow flying SeaRey. It seems to be happening with increasing frequency now that ADS-B is more commonly in use. The hazard of aircraft locating and inappropriately following other aircraft has not been addressed. Masking aircraft specific ADS-B information would eliminate some of the close curiosity encounters.
A pilot of a amphibious kit airplane reported another aircraft intentionally tried to fly towards them to look at their aircraft.