Thank you to Weather Underground for posting factual weather records so there can be real science.
I found this looking for correct diagrams on Google Images, posted on
NWS San Diego 'Offshore' wind prediction graphi 9-26-13

Look up 9/27/14’S “SHORE” winds in Oceanside: ENE winds are 3-5 mph at 8-9 a.m., and West winds kick in by noon and blow 7 hours from 7-21 mph, exactly as they do here in L.A. on days weathermen call “offshore” days:

If West winds dominate in speed and duration at the “shore,” then “offshore” is not a correct way to name these dry winds.