In "Casino" Robert De Niro's character puts $2M in jewels in a safe-deposit box that even he doesn't have the key for (he naively gives the key to his wife- but that's another part of the plot) He narrates that the jewels are "in case he got in trouble". Ostensibly so he could pay off kidnappers.
I have the "poor man's" version of De Niro's safe-deposit box, a Rolex Submariner. Readily convertible into US$3-5K cash (at least) in pretty much any large city in the world. It's always on my wrist. If I needed the money desperately and couldn't access my accounts, I have my beloved watch.
Be careful as there are rumors of people using machetes to separate these watches from their owners on the street in certain countries just to reduce time, effort and risk.
I guess that's safer than leaving your cash out on the kitchen table, or maybe at a bus stop...but not by much if your threat model is highly sophisticated thieves/attackers capable of breaking into a safe-deposit box and/or kidnapping your family and ransoming them.
I'd rather not know what time it is than wear a Rolex. I would be self-conscious about people thinking I was that vain and materialistic, assuming it's fake, and that I was a poseur. Get a money belt if your point isn't just to show off and you're not asking to get rolled.
Unless you go for the yellow gold or two-tone (gold/steel) models, 95% of the people won't no that you're wearing a Rolex. Regular Submariner or Datejust is pretty nondescript and doesn't scream Rolex at all. Only other watch nerds will notice.
