The beach is great...but the beach is expensive! I normally inform out of town visitors that the closer you get to the water..the higher the price! I think WLA is the closest you will get but you will need another 1,000 per month or so to lease even there.
There are safe and great places in Santa Monica to live but at $900 your not going to be able to find a studio in that price range. I just rented a studio in Santa Monica close to the water for $1250 per month. If your trying pay the same rent Long Beach is more bang for your bang for your $ buck.
Good luck in your home search.
Carlos Juan Cuevas
Real Estate Consultant
Keller Williams Realty-Brentwood
CJC Realty Advisors Inc.,
11812 San Vicente Blvd, Suite.#100
Brentwood, CA 90049
It you are willing to live Santa Monica adjacent, you may be able to find a 3 bed a little cheaper, but the "Westside" is expensive in general. Good luck!
Try using http://www.padmapper.com for now to just give yourself an idea of rent pricing along the water.