Oksana Grigorieva's New Home -- Bankruptcy? I Left My Valley Dump For A Beach Pad

Beware rich Westside dudes ... Oksana Grigorieva is on the prowl in Santa Monica ... she's moved into a luxurious beachfront home with stunning ocean views ... even though she's bankrupt.

Grigorieva -- who claimed she only had $10 cash when she filed for bankruptcy in Feb. -- moved out of the Valley house Mel Gibson got for her and their kid ... and into a luxury hi-rise at the beach.

We're told Oksana's ditched her Valley digs because the house flooded during a big rainstorm last month -- the same weekend she was seen trying to crash a post-Oscar party.

We're told Mel offered to move her temporarily into another place in the Valley but Oksana said "nyet" ... she wanted an upgrade to Santa Monica. We're told Mel refused to pay so Oksana somehow got enough money together to pay for the more expensive oceanfront rental. So how'd she do that?

Now she's bragging on social media about her new lifestyle ... posting pictures of her to-die-for ocean views and the chi-chi Westside restaurants where she hangs out.