Small Aircraft; High Wing; 1 Eng; Fixed Gear
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Flight Crew Last 90 Days 300; Flight Crew Total 16700; Flight Crew Type 16000
Communication Breakdown; Confusion; Situational Awareness
Conflict NMAC
Flight Crew Took Evasive Action
Human Factors; Procedure
The Heli Pilot was not talking on the radio; but had it on.  I found out later in the day he was unsure where he was.  He heard my radio calls but didn't know how to process them.  Didn't understand N1ame & Name 2 Beach or where they were.  I have T-CAS & ADS-B that are working perfectly; he didn't have transponder turned on & I'm not sure if he had ADS-B.  My system would have warned me he was there.  I was descending through 500 feet on base-leg 1/2 mile off shore to land on the Name 1 Beach to pick up clients.  I checked the 3 planes on the Name 2 beach to my left to make sure they were not departing; then focused on my landing paying close attention to the two Bears sleeping on the beach and folks taking pictures; maneuvering around and beyond them.  Then suddenly there was a Heli at my altitude 100 feet off my right wing. At the end of the day I have discussed this with Company that own the Heli & the Pilot.  I believe it to be resolved.
Pilot reported a NMAC with a helicopter.