First to answer Stephen's question. Chronograph's measure time, think stop watch. One function then is simply elapsed time. The tachometer function can be used to measure time against distance, start/stop the chrono at the beginning and end of a measure kilometer or mile and you have determined your speed in kph or mph. I agree that it's weird to have such a function on a watch called Deep Sea (thinking that implies that it's a DIVE watch, which it is not).
Second to the vote count - I see the counts across two record as 5 for Deep Sea 4 for Chrono Generic WITHOUT my vote. One of the three watches seems to be heading for the dust bin as there is some confusion about it
I think Mark makes a compelling argument that it MIGHT be a Deep Sea but there is just no ad or hang tag. The ad he features is a completely different model.
Chrono, Generic, all three of them, if/when we find more proof we can update.