Billy Joel rocked the boat with his maybe girlfriend earlier this week -- taking her on a pimp-ass yacht ride down the Hudson River in upstate New York.
According to reports, the mystery woman is an exec at Morgan Stanley in NYC -- so girl obviously has experience hitting the mother lode.
As for the boat -- "Captain Jack" was not at the helm ... we hope.
Billy Joel's New Lady
A Hull of a Woman
10/30/2010 8:30 AM PDT BY TMZ STAFF
Get TMZ Breaking News alerts to your inbox