Aiming for the weekend, and banging around in the garage, I swapped out my Speedmaster for a Seiko version
the Seiko 7a28-7049 Super 100 Chronograph
SteveG has a great appreciation page for the details of this watch, e.g. 1/10th second, splits, engineering details, design, ... http://watchpics.com/watches/others13/Mediums/mseiko7a28.html