how long you there for ? If your stay over-laps any of the Prospector's club meetings (~30 min. from Venice beach), then I'll bet if you chatted with locals at the meeting, you'd find someone willing ... with a deposit, to loan you a beach-able machine. http://prospectorsclub.org/
Or just find the listings for any dealer (except for big-box stores) and simply call and ask "do you rent as well ?" Sometimes a small-time dealer (who just deals as a hobby) will sometimes rent his personal machine.