did a quick check on Chula Vista
It took some digging, but one of the newsletters from the Chula Vista Marina seems to show that they take a middle-of-the-road policy that would probably work for an occasional "stayaboard":
From their April 2010 newsletter:
Many of our boaters enjoy legal Liveaboard status and pay hard earned money for the privilege. Chula Vista Marina, like other marinas, is
limited in the number of total boats whom we can offer this status to.
It is disheartening to these Liveaboard Tenants when they see other
tenants enjoying this privilege as a Sneak- Aboard who is effectively
living aboard without the legal status and without paying.
Anyone who stays on their boat more than 3 nights a week is
considered to be living aboard.
If, occasionally, you plan to spend longer than 3 nights on board in any given week, just let the marina office know. We will be happy to issue you a Vacation Liveaboard Permit for a short stay at no cost to you.
Rates for a 35 footer seem to be $13/ft or $455.