SMA PLT MAY HAVE PENETRATED TCA ON CLIMB OUT.

Narrative

THE FAR NW CORNER OF THE SEA TCA MAY HAVE BEEN CLIPPED WHILE CLBING TO VFR CRUISE ALT OF 5500' MSL. NAV WAS BY PILOTAGE FROM CURRENT SEA TERMINAL AREA CHART. THIS CORNER OF THE TCA IS NOT WELL IDENTED BY GND REFS (AN AREA OF UNREMARKABLE WOODED LOW HILLS AND VALLEYS) AND ON THIS DAY THE AREA WAS MORE POORLY DIFFERENTIATED BY A LAYER OF GND SMOKE AND POLLUTION HAZE. IT IS NOT KNOWN WHETHER AN ACTUAL INCURSION OF THE TCA OCCURRED; BUT THAT CORNER MAY HAVE BEEN MISIDENTED AT THE INITIAL REF CHK PRIOR TO CLB THROUGH 5000' MSL. AN ADDITION GND REF CHK 1 MIN OR SO LATER INDICATED WE WERE NOT AS FAR BEYOND THE TCA AS EXPECTED; LEADING US TO SPECULATE ON WHETHER WE HAD BEEN CLR WHEN WE INITIATED OUR CLB. I BELIEVE THE CAUSE OF THIS POSSIBLE INCURSION WAS THE LACK OF EASILY IDENTED TCA BOUNDARIES IN THIS CORNER. THE ACFT IS NOT EQUIPPED WITH DME; BUT I COULD HAVE USED THE SEA VOR AND THE PAE VOR TO IDENT THE CORNER IF I HAD REALIZED THAT THE GND REF IDENT WAS AMBIGUOUS. NEXT TIME I WON'T RELY ON PILOTAGE; BUT FOR OTHERS FLYING VFR IN THIS AREA; A TCA BOUNDARY ADJUSTED TO A MORE POSITIVE GND REF WOULD BE HELPFUL. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: PLT NOW NOT SURE HE ENTERED TCA. NO FAA INDICATION THEY WERE AWARE OF ANY INCURSION.