I was an electronic watch guy from when they came out. Anyone old enough here to remember having to push a button to get the red LED display up to read the time?
Yes I remember those. They ate batteries like crazy. Want to use one for 10 years, you better buy a case of batteries to go with them.
There are watches with batteries that claim to last up to 10 years. Solar watches also claim to last 10 years since they give the rechargeable battery that long. But the rechargeable battery is replaceable too. Although after 10 years I probably want a new watch anyway.
My first wife gave me an Accutron when they came out...kept terrible time even after multiple visits to the factory for repairs.
Mine didn't last long. I think it lasted a few months and once during the winter I touched a light switch and static electricity hit my hand. The watch display went blank and never worked again.
Then I went to the Casio stuff with all the timers and other crap, but batteries were always a problem and I was never confident they were staying water resistant/proof after the first battery replacement.
Casio is one of my favorite watches since they have all of the cool stuff in most of their models. Damn like 99% of them are made out of plastic.

I don't think you have to worry much about that water resistant/proof stuff if the o-ring isn't flattened, nicked, or if there isn't any dust and dirt anywhere. Heck some of them are good past 100 feet of water. If my super quick calculations are correct, that is like over 30PSI (probably more like 60PSI - okay I spent more time posting this then I did trying to figure it out,). What are you going to expose it to being that high? Clean it with a pressure washer perhaps?
Now I'm back to my Seiko, analog, mechanical, self winder. Yeah, I have to adjust the time by a minute or two every few days and change the date every other month but it keeps on working and never needs a battery. Another side benefit is that it won't stop if there's an EMP, the prepper in me. All the other electronic whizz bang time keeping dodges will be worthless if that ever happens.
Ah... I bought one of them in the 70's and I still have it. Wore it everywhere including working on cars and motorcycles. The crystal got all scratched up. All I needed was the crystal and I could change it myself. Well I heard the figure of 50 bucks and I said the heck with that idea and moved on.
Although talking about an EMP... if that did happen and most electronics do fry, I don't think I would be concerned about the date and time anymore. As I would be too busy with the chaos going around to care.