William, 30, was part of an RAF search and rescue crew scrambled at around 12:30 a.m. Tuesday to help find a 41-year-old dog walker who had gotten lost in raging seas at Blackpool, Lancashire. Sadly, the RAF Sea King helicopter was unable to find the stricken man, and searches by coastguard crews were continuing into early Wednesday.
Kate, meanwhile, was believed to be ringing in the new year at home with her parents in Bucklebury, Berkshire, where she and William spent their Christmas Day.
At his RAF base in North Wales, William was on the first responders' shift from early New Year's Eve into the start of the New Year, PEOPLE was told. He was also to spend a second 24-hour shift on or near the base as part of a second back-up crew.
As for Kate, she was seen at a gas station on Sunday stocking up on Mini Cheddars snacks, according to one eyewitness.
William is expected to spend much of the early part of the year "concentrating on his flying," a Palace source tells PEOPLE, and he and Kate are not expected at any royal engagements in the first few weeks of '13.