Location of the Gulf of California in the region.
The borders of the sea are approximately based on those from the IHO's "Limits of Oceans and Seas" Draft 3rd Edition, 1953, but they're also close to those from the IHO's "Limits of Oceans and Seas" Draft 4th Edition, 2002.
(Winkel III projection centred 0° W and standard parallels at 50°28'.)
The map was created using data from Natural Earth and International Hydrographic Organization, IHO; Sieger, Rainer (2012): Limits of oceans and seas in digitized, machine readable form. Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, PANGAEA, with mapshaper.  (The former data source is in the public domain, the latter under CC BY.)  For reproducibility purposes, this was the set of scripts used.

The style of the map was generally intended to follow that of the German Locator maps project, except for the highlight colour of the sea, for which dark blue (#4790c8) was used.
Own work
Aplaice