California state waters are open to recreational groundfish fishing effective April 19, 2024. Federal recreational groundfish season opened on April 1.   
https://wildlife.ca.gov/Fishing/Ocean/Regulations/Groundfish-Summary?utm_medium=email&utm_source=govdelivery#central-north

The way I read it, in the waters near me, Monterey Bay, we can fish 300 feet and deeper from now until April 30.  Anything shallower is still closed.  Come May 1st until September 30th , we can fish 120 feet and shallower only.  Then all October is only 300 and deeper, November is back to only 120 and shallower and December is back to only 300 and deeper.
Is this how others interpret this?

Yes, that is correct! You also need to have a descender on board.

So for us nearshore no joy....So May1 all of California season is open its not all broken up in different counties ?

In general, yes, on May 1, all of California is open to 20 fathom or less to rockfishing. But areas south of Point Lopez are already open since April 1st. Please check the regulations here:

https://wildlife.ca.gov/Fishing/Ocean/Regulations/Groundfish-Summary

The way I read it, in the waters near me, Monterey Bay, we can fish 300 feet and deeper from now until April 30.  Anything shallower is still closed.  Come May 1st until September 30th , we can fish 120 feet and shallower only.  Then all October is only 300 and deeper, November is back to only 120 and shallower and December is back to only 300 and deeper.
Is this how others interpret this?

Yes but "300 feet and deeper " is defined by the 50 Fathom line coordinates and some parts that are reachable are as shallow as 220' or 250' or so. Likewise 120' and shallower is defined by the coordinates, not the depth contour.
I just finished entering the coordinates in Navionics on my phone and saving them as a route, which creates the lines. I'm not sure if I can get them into my FF via the card.

apparently as of 4/19/24 looking at the reg books

SF area: https://wildlife.ca.gov/Fishing/Ocean/Regulations/Fishing-Map/San-Francisco#rockfish

MBKA area: https://wildlife.ca.gov/Fishing/Ocean/Regulations/Fishing-Map/Central-North#rockfish

still 50 fathoms for my areas, until 5/1

While I realize we need a descending device, at what depth do you need to use it for the fish to survive?

In my experience around 70-100+fow is where I've brought fish up that bloated and needed to be descended with a device. 

All depths, all fish, no matter what the appearance.

Even fish caught in <10 fathoms have a higher survival rate of descended vs surface releasesed.

For instane, CDFG uses a 21% mortality rate of Quillback caught in <10 fathoms and released at the surface.  When a descender is used, the mortality rate is 9%.  They make no distinction on the physical appearance of the rockfish.

-Allen

wow! good to know

Does this mean that Cabezon and greenlings are unfishable (from boat) from April 1 - April 30 and Dec 1- Dec 31? Not sure how common they are offshore, but I imagine they pop up every now and then.