Guías de compra

One is a machine with three hundred moving parts that loses time every day. The other is accurate to seconds per month and costs less. Here is why anyone chooses the first one.

Case diameter is the number every brand advertises and the least useful one for working out whether a watch will fit. Here is what to measure instead.

A watch rated to 50 metres cannot be worn swimming. The ratings are laboratory figures, not depth limits, and the difference matters.

The crystal is the part of a watch you look through every time you check the time, and the part most likely to show damage. The three materials behave completely differently.

Most first watches are bought on the wrong criteria — brand, diameter and a photograph. Here is the order the decisions should actually be made in.