The Flight star was spotted on the beach on 28 December (12) with his wife of 29 years.
The Washingtons later boarded a yacht for an afternoon at sea and they also hit an island restaurant to celebrate in style.
It's not known if the couple will be among the guests attending Russian billionaire Roman Abramovich's New Year's Eve party on St. Barts.
The Caribbean paradise has become a star-studded hotspot this winter - Kate Moss, Russell Simmons, model Stephanie Seymour and Sean 'Diddy' Combs have all been spotted there in recent days and Naomi Campbell and movie mogul Harvey Weinstein are expected to fly in for the big New Year's Eve bash on Monday (31Dec12). Kings of Leon will reportedly headline the party.