Here is a site that does a plausible job of calculating the depth at 12.3mm (38mm) and 12.46 (42mm) based on the known length. Keep in mind this is maximum depth and at the highest point of the sensor. Most watches have a flat back, so the 'on wrist' perceived thickness will likely be considerably less since the 'point' of the sensor will rest between the ulna and the radius (natural divot). The watch body (sans sensor) of the 42mm is 10.6mm deep which will probably be closer to what wearing it will be like.
Also this is the same or less than my Garmin 620 at 12.5mm. The Moto 360 is about 11%/12.4% thinner at 11mm and no HR sensor.
Is 12.3mm/12.46mm thin? No
Is it as thin as Apple would like? Probably not
Is it as thin as Jony Ive & Marc Newson would like: No
Is it as thin as the 2ed Gen? Probably not
Is it as thin as I would like? No
Despite all of the above the aWatch will fall in the mid thickness range and is NOT a thick or bulky watch.
Thank you for this sensible post.
I agree totally with all your 'Is it as thin' points, and I'm confident the future will prove you right.
This is a mirror image of screaming how the iPhone1 or iPad1 was the perfect thickness, and now people year later and laughing at how thick they were back then.
It's as if people think Apple would not of loved to have stunned the world by bringing out exactly what they have done, but it was only 5mm thick.
People would be raving about how did they do it, and amazed such a feat were possible.
Boasting of how amazing Apple was, and that no other maker could do it, and how fat and stupid all the other brands of smart watches look now in comparison.
Of course we all know THAT would then be the products major point, and Apple would be showing the watch of sideways on all the time as opposed to front on, and angled just right to hide the thickness most of the time.
We just have to live with what they have made for a v1.00 and accept that they best compromise they've come up with for now.
I just find it funny how people will proclaim it's perfect, when we know dam well, if if was thinner, then THAT would be proclaimed perfect.