Forskellen på to seiko modeller ?

[Joepete]

The SAT term is just an expression, John, and has nothing to do with "withstanding mixed gas", as I understand things. I might be wrong though, but until we get one of the professional diver´s on to this thread, this is how I understand things:

The whole point is that when You go for a professional dive at perhaps 175 meters, You use "mixed gas" AND you need to use a helium chamber when ascending. It is therefor crucial that Your watch (if using such an "old-timer" ) can cope with helium and take the very big pressur at those depths.

I am not quite sure from where You get the 10 minute vs 35 minutes ... ? I would trust the MM300 professional diver´s watch to be descended as long as the diver would want it to be

I have sent SK an e-mail to get his assistance on this - I think we need it