NMAC BTWN 2 SMA SEL ACFT; ONE ON FINAL AND THE RPTR TURNING FINAL AT A UNCTLED ARPT.

Narrative

I ENTERED A L DOWNWIND AT 800 FT MSL FOR FULL-STOP LNDG AT VENICE. I BELIEVED I WAS #3 IN TFC; FOLLOWING A PIPER COMANCHE OVER THE APCH END OF THE RWY AND A PIPER SEMINOLE ON EXTENDED FINAL. I ANNOUNCED MY PRESENCE AND INTENTIONS ON DOWNWIND ON CTAF AND HAD BEEN LISTENING TO RPTS FROM THE COMANCHE AND SEMINOLE. WHEN I WAS AGAIN THE SEMINOLE; I STARTED MY TURN TO BASE AND CALLED BASE ON CTAF. AS I STARTED TO TURN FINAL; I WAS ALERTED TO CESSNA TFC BY AN ACFT WAITING TO TAKE OFF. I SAW THE CESSNA IN MY 1 O'CLOCK POS; SLIGHTLY ABOVE. I TURNED R (N) THEN L (W) AND PASSED BENEATH AND BEHIND THE CESSNA WHICH CONTINUED ON APCH. I WENT AROUND; PARALLEL TO AND TO THE R OF RWY 13; REJOINED TFC; AND LANDED. IF THE CESSNA HAD BEEN RPTING AS IN THE AIM; I BELIEVE THE INCIDENT WOULD NOT HAVE HAPPENED. SINCE I HAD THE OTHER 2 AIRPLANES IN SIGHT; I DID NOT PROPERLY CHK FURTHER OUT ON THE FINAL APCH FOR TFC. EXTENDED PATTERNS CONTRIBUTE TO THIS KIND OF OCCURRENCE. MY ACFT WAS A PIPER WARRIOR; THE OTHER; A LIGHT-COLORED; SINGLE-ENG CESSNA (152 OR 172).