Just two weeks ago in late April, Microsoft founder Bill Gates popped by the Harvard campus to speak with the undergraduates of his alma mater (although he was a drop-out, he eventually received an honorary law degree from the University in 2007, three decades after his class graduated).

On his tour to the Harvard Microrobotics Lab and the Harvard Biodesign Lab, he viewed demonstrations of ongoing leading research, including robotic bees and soft robots. Bill Gates then took on a casual Q&A session with the students, and here we spied a dive watch when he rolled up his sleeves.

A closer look at his watch:

So, what could be on the wrist of this guy in a plain good ol’ olive wool sweater who happens to have a net worth of USD 90.5 billion?

Well, the answer came almost without a surprise, as Bill Gates is known for his frugality when it comes to watches.

On the wrist is the Casio Quartz Diver 200m WR (Reference: MDV-106-1A) which one can purchase at Walmart for USD50 (or perhaps even lower, if you use coupons!).

The MDV-106-1A from Casio in 44mm stainless steel case is one of the brand’s classic dive watch with a water resistant of 200m and other standard dive watch features, such as a uni-directional rotating bezel and a screw down crown. This highly legible quartz watch has a battery life of 3 years, almost perfect for the lifestyle of a busy billionaire!

This concludes today’s Spot the Watch, but do let us know in the comments below if you agree with Bill Gates’ choice or, if you have better suggestions for him!