You can fish as many rods/ lines in saltwater as you want. However the second you put a ground fish on the boat (rockfish, lingcod, sculpin, cabezon, greenling) you're then restricted for the remainder of your trip to one Rod/ line w/ no more than two hooks. So I see it a lot, but no fly lining while rock fishing, or jigging while dropper looping!
There have been a few times fishing with my uncle when we have fly lines out and droppers hopping for a yellow and we wind up pulling up a big ole red and the question comes out from me "are you sure you wanna keep keep it"?!?!
It does not matter what your targeting unless it is ground fish. All multiple Rod fishing legally is supposed to come to a close when you decide to keep any of the given fish. It also mentions in the post that "Bays" fall into the regs. Anything with saltwater.
Only reason I know this is bc a few yrs back I discovered the Alabama rig and no one could give me an answer on how many hooks I could use with it. I only knew the fresh water regs. I called DFG and everything. I finally came across this after a cpl weeks of searching.
https://nrm.dfg.ca.gov/FileHandler.a...umentID=116558