straight from the DFG website.
"Lobsters may only be taken by hoop net or by hand. Divers may not possess any hooked device while diving or attempting to dive for lobsters"
For the full regs for everything south of point conception here is the link:
http://www.dfg.ca.gov/mrd/mapregs5.html
I seem to remember having DFG checking us on the OB pier and making sure lobsters were caught by net.