Hi Ya Ref
You are correct..we prefer to launch at Hearts Desire Beach in Tomales Bay State Park for many reasons.
There is a beautiful park setting at Hearts with bathrooms, showers , fresh water, many barbecue pits, swim area, hiking trails lawn, shaded trees and picnic benches.
The most senic part of the 15 mile long Bay is on the western shoreline side ,as is the park, so there is no need to paddle across the bay before seeing the sights.
I believe trailers are ok but all craft must be hand carted to the water south of the swimming area and there is no launch ramp.
We have never launched from the Marconi/opposite side as we prefer to paddle the western shoreline.
There are several sites to launch along Hiway One but most folks launching there seem to just cross the bay to a beach or two and go back, we prefer to paddle along the length of the bay as far as we can and as conditions and time allow before heading back .
Have a good one