Patek Philippe celebrates 20 years of its luxury-sport Aquanaut model this year with two significant new references. One is the technically groundbreaking Ref. 5650 “Advanced Research” edition, which we covered in depth during Baselworld. The other is this week’s Watch to Watch, the Aquanaut Ref. 5168G — the first Aquanaut in a white-gold case and, at 42 mm in diameter, the largest in the collection.