In Marina del Rey, for example, Marina Harbor allows liveaboards, though the minimum boat size is 40' with the LA County approved "Live Aboard Sticker". Rents on a 40' boat are $1000/month and they charge an additional 50%/month (~$500) for liveaboards. I don't think you are going to find legal liveaboard
in MDR - the place has become so anti-boating, with all the redevelopment, eliminating small-boat slips....
Per the county regulations
, they allow 3 days/week liveaboard
Liveaboards in Marina del Rey must comply with County Code 19.12.1110, which prohibits a person from using a vessel as an abode in excess of three days within any one-week period, unless authorized by the dockmaster where the boat is anchored, and issued a liveaboard permit by the Harbor master at the L.A. County Sheriff Department. It is completely within the discretion of the local dockmaster as to if and whether a liveaboard situation will be authorized in any particular marina.
A permit will only be issued by the L.A. County Sheriff Department Harbormaster upon compliance with the following: (1) compliance with the requirements of seaworthiness as described in County Code 19.12.1060; (2) installation of a federally approved marina sanitation device of self-contained portable toilet approved by the Harbor Master. Liveaboard permits are valid for a period of one year. (3) proof of authorization by the dockmaster.