Kate and her family are already on Mustique, and William is on his way

By Simon Perry
Updated January 21, 2012 03:30 PM

It looks like it’s going to be a true family vacation for the Duchess of Cambridge: Her husband, the Duke of Cambridge is about to join her for some sun.

William is expected to jet out from blustery Britain to join Kate on her luxurious Caribbean getaway – once his military shift schedule allows, PEOPLE has learned.

This would be the last extended break before William heads to his assignment on the Falkland Islands as an RAF search and rescue helicopter pilot for six weeks next month.

While William was working in north Wales this week, Kate and her family left London’s Gatwick Airport for St. Lucia and then on to Mustique.

The luxurious private island is a regular holiday hotspot for the Middletons, who invited a group of islanders to Kate and William’s wedding last April. The Duke and Duchess have been frequent visitors to the isle, too.