Excellent topic Stewart, thanks for this lead!
The tool watch is w/o doubts the category I am in for watches, possible exception only the Carrera 1964 re-edition that I am btw wearing right now.
I am putting two constraints on my selection:
- Chronos only (which rules out some very tool watches like the Superprofessional)
- Watches that I either own, or have owned or would like to own.

My thoroughly-pondered selection would be:

All-Heuer set, in preferential order:
1. The AMI : L5100-powered, so a workhorse of a movement; mineral crystal to withstand most abuses; military heritage; sandblasted finish; stealth look - the whole lot. Sadly, the one I do not own :-(
2. Autavia 11063V: the largest and bulkiest of them all, officially rated to a 200m depth for WR, big bezel, large pushers... the ultimate (and also one of the very last in line) of the Autavias.
3. 510.500: most of the AMI features, L5100 etc. at a tiny fraction of the price; plus: polished finish that can be restored very easily if scratched. This is the one I really wear whenever I am likely to be caught out in rain or in any potential "watch-endangering" situation like on the beach.

All-non Heuer set, in preferential order:
1. Sinn 756 : hardened steel case; cockpit-clock look dial; DEKRA crash test survivors; magnetic field protection and - not least at all - readily available and with a decent used market.
2. Sinn 157 Ti Ty : the AMI's cousin, but in a titanium case which makes it antimagnetic by definition and so more comfortable on the skin both in cold and hot weather. My go-to watch more and more recently.
3. Omega Mark IV : the ancestor of the L5100, with an integrated case and a very very thick crystal; housed pushers etc. Now gone to my nephew but one I really used to wear a lot.

The magnetic field protection can seem a fuss but my 510.500 actually got magnetized in an airport security check, so now I am more careful on this side...

Cheers,
Fabrizio