So, these pics of Elizabeth and Dominic as Diana and Charles on a yacht are quite a sight to behold:
Per the Daily Mail, it definitely looks like they're re-creating the trip Charles and Diana took in Italy with their sons for their 10-year wedding anniversary in 1991 — the year before they announced they were separating.
As for The Crown, filming is taking place in Palma De Mallorca aboard the Christina O yacht — once owned by Jackie Kennedy and Aristotle Onassis.
Of course, because it's The Crown, the look is pretty spot on:
However, it looks like the fashion inspo may actually be from the pair's visit to the Universal Exposition of Seville rather than the trip itself.
Alas, The Crown Season 5 won't actually be out until November 2022. It'll be the show's penultimate season and will cover the breakdown of Charles and Diana's marriage, as well as her death.