The latest item in Patek Philippe’s Aquanaut collection is the ref 5167/1 which is based on the ref 5167A which debuted last year. The main difference between the ref 5167/1 and the ref 5167A is the omission of the signature Aquanaut rubber strap in lieu of a stainless steel bracelet. The bracelet which has polished steel center links has been designed to blend in with the Aquanaut theme and emphasizes the sturdy physique of the watch.