GA PLT ERRONEOUSLY ENTERED CLASS C AIRSPACE AT SBA.

Narrative

ON A VFR FLT FROM OCEANO TO SANTA MONICA; CA; I WAS APCHING RZS (SAN MARCOS) VORTAC; TRYING TO STAY 500 FT BELOW VARIABLE CLOUD BASES. UPON REACHING APPROX 20 NM FROM RZS; I REALIZED THAT I WOULD NOT BE ABLE TO CROSS THE RIDGE THERE BECAUSE OF CLOUD OBSCURATION. I THEREFORE DECIDED TO DIVERT TO THE W WHERE I COULD SEE A CLR AREA UNDER THE CLOUDS ABOVE THE RIDGE; AND DID CROSS THE RIDGE AT APPROX 3700 FT MSL. I THEREUPON ENCOUNTERED MORE CLOUDINESS AND DROPPED DOWN TO 3000 FT; LOOKING FOR TFC AND TRYING TO AVOID CLOUDS AND NOT GET INTO IFR CONDITIONS. ABOUT 3 NM W OF SANTA BARBARA ARPT I SPOTTED THE RWYS AND CALLED SANTA BARBARA APCH ON 120.55; IDENTING MYSELF AND ASKING FOR RADAR ADVISORIES. I WAS AWARE OF THE CLASS D AIRSPACE AROUND AND ABOVE SBA ARPT AND MAINTAINED 500 FT ABOVE ITS CEILING; BUT I DID NOT REALIZE THAT I HAD INCURRED INTO CLASS C AIRSPACE UNTIL I WAS SWITCHED TO 125.4 SANTA BARBARA APCH AND GIVEN A PHONE NUMBER TO COPY AND CALL. UPON LNDG AT SMO; I CALLED THE SBA TWR OPS SUPVR AND EXPLAINED THAT I INADVERTENTLY TRESPASSED INTO HIS CLASS C AIRSPACE WITHOUT CLRNC BECAUSE OF THE ADDITIONAL WORKLOAD OF AVOIDING CLOUDS AND WATCHING FOR TFC DURING MY DIVERSION. ORDINARILY IF I CROSS THE RIDGE AT RZS; I DO NOT HAVE TO WORRY ABOUT CLASS C INCURSIONS; BUT IT BECAME A FACTOR WHICH I HAD FORGOTTEN ABOUT WHEN I DIVERTED. THE OPS SUPVR INFORMED ME THAT HE HAD ME ON HIS RADAR ALL THE WAY AND THAT I WAS NOT A FACTOR TO ANY TFC IN HIS AREA. HE ACCEPTED MY APOLOGIES OR SO I FELT AFTER OUR CONVERSATION AND I TOLD HIM THAT I THINK I HAVE LEARNED MY LESSON; TO WIT: REVIEW MY VFR CHARTS OF MY RTE BEFORE VFR FLTS; BECAUSE ONCE AIRBORNE; ADDITIONAL UNFORESEEN WORKLOADS MAY NOT BE CONDUCIVE TO CHART STUDY DURING CRITICAL PHASES OF THE FLT. I SUPPOSE I COULD HAVE AVOIDED THE WHOLE SIT BY FILING IFR; BUT I WAS INTENT ON GETTING BACK TO SMO AS EXPEDITIOUSLY AS POSSIBLE; AND FELT THAT VFR WOULD BE THE BETTER CHOICE.