Dr. Ito's thorough analysis of mechanical watches!! Vol.35 ~ How to use the Yacht-Master II

Hello everyone!

This column discusses mechanical watches from an engineer's perspective. For our 35th installment, we will be discussing:

"How to use the Yacht-Master II"

We'll be exploring this topic today.

The Yacht-Master II, developed as a professional model for yacht races, features an incredibly luxurious mechanism. It boasts the world's first regatta chronograph (countdown timer), and its unique operating method is one of its charms, making one wonder if a similar mechanism will ever appear again. Even among owners, some may not know the official way to use the Yacht-Master II, so I'd like to explain it in detail today.

If you're interested in the Yacht-Master II, please use this as a reference!

What is the Yacht-Master II?

Sales period: 2007-2024

Movement: Cal.4160 (early), Cal.4161 (late)

Features: World's first chronograph with a mechanically programmable countdown timer

Initially, only solid gold models in 18K Yellow Gold (18KYG) and 18K White Gold (18KWG) were available. Later, a combination model of Stainless Steel (SS) & 18K Everose Gold (18KERG) and an all-SS model were added.

How to use the countdown timer

A countdown timer is provided to measure "how many minutes are left," which is crucial for the start of a yacht race.

While it may seem complicated at first glance, it's easy to use once you get the hang of it.

A Start/Stop push button

B Reset push button

C Countdown second hand

D Countdown minute hand

E Bezel that rotates 90 degrees

[Step 1]

Rotate the ring bezel (E) 90 degrees counterclockwise and press the reset button (B) at the 4 o'clock position. Due to the bezel rotation, the push button remains pressed.

Unlock the crown and turn it upwards to set the countdown time (minutes). Turning the crown moves the countdown triangular hand (D), allowing you to set it in 1-minute increments up to a maximum of 10 minutes.

In yacht races, there are predetermined countdowns of 5 or 10 minutes, and the watch is designed to precisely accommodate them. This function allows you to change the countdown start time according to the yacht race you are participating in or watching.

Note that you only need to unlock the crown; there's no need to pull it out. This is the same position as for manual winding during normal use.

Screw the crown back into its original position and rotate the bezel 90 degrees clockwise to its original position. At this point, the reset button that was pushed in will automatically return. The countdown timer is now set.

Press the Start/Stop button (A) to begin timing with the chronograph hand. Pressing the Start/Stop button again stops the chronograph hand. To resume timing from a stopped state, press the same button again. To reset, press the reset button (B) while the timing is stopped, and the hands will reset. The countdown minute hand has an advanced function that returns to the pre-set time.

How to use the synchronization function

The synchronization function allows you to reset the chronograph second hand to 12 o'clock by pressing a push button during a countdown measurement, and then resume the countdown by releasing it.

Even if you start the chronograph with the starting signal, there can be slight discrepancies. In such cases, you can use this synchronization function to correct the discrepancy by aligning it with the second or third signal.

It also works in conjunction with the countdown timer: if the chronograph second hand is past 30 seconds, the countdown hand advances by one minute; if it's not past 30 seconds, it moves back by one minute.

Summary

The Yacht-Master II achieves its regatta chronograph (countdown timer) mechanism by linking the rotating bezel with the movement. This mechanism is also used in the Sky-Dweller and greatly contributes to balancing special functions with legibility.

The existence of the Yacht-Master II is thanks to this patented Rolex technology. Although it has been discontinued, I personally believe there's a high possibility it will be valued as a special model in the future.

I hope this article provided useful information and sparked some interest in luxury watches! Also, if you have any questions, please don't hesitate to ask directly; we'll be sure to answer them thoroughly. We look forward to your visit and inquiries.

Stay tuned for the next installment! See you then!