Rolex Lady-Datejust 79178

The case measures 26mm across, with a 13mm lug width. Case material: 18k yellow gold. Case size alone is a poor guide to how a watch wears; lug-to-lug length and how the bracelet drops off the case matter more, which is why we suggest trying one on before you commit.

It is rated to 100 meters, about 328 feet. That is enough for swimming and snorkeling, but not for scuba diving. One caution that applies to every watch on this page: a water resistance figure describes a new watch with fresh gaskets. On a piece that is years past its last service, treat the rating as unknown until it has been pressure tested.

Rolex produced this reference from 1995 to 2001. Production years matter when you are valuing one, because dial, bezel and bracelet details often changed inside a single reference run.

791 = Lady-Datejust 26mm latest 5-digit era; 78 = full 18k yellow gold with Presidential bracelet. Reading the reference is the fastest way to confirm that a watch is what the seller says it is, before you get anywhere near the movement.

Lady-Datejust 26, solid 18k yellow gold, Presidential, latest 5-digit. Collector nicknames are not official Rolex names, but they are what people actually search for and what they are called across a showroom.

Yes. We buy this reference outright, and we lend against it if you would rather keep it. We are a family-owned San Diego buyer established in 2006, our appraisers are GIA-trained, and the appraisal is complimentary with no obligation to sell. You can bring it to our Gaslamp showroom at 907 Sixth Ave or start online. If you are looking to buy this reference instead, tell us and we will let you know when one comes in.