The Omegamatic is more like the Seamaster 120m than the 300m Professional. The Omatic uses the same basic case as the Seamaster 120m and mid-size SMP, and like the 120m quartz, the Omatic is thinner than the both the SMP quartz and auto. It is also quite a bit lighter than my SMP mid-size automatic. The bracelet is not the same as the SMP with large folding clasp, but it is the same as the 120m where the clasp is hidden underneath the bracelet. Omega literature states that the crystal is lightly domed on the Omatic, but it appears flat to me when compared to the SMP crystal. The hands tick at one second intervals like a quartz watch, because is essence it is a "self-winding quartz." Another item to note is that there is no tritium dot on the bezel at the 0/60 minute position like you will find on the SMP. Why the Omatic is 200m and not 120m or 300m is anyone's guess - I suppose that most swiss diving watches (i.e. Tag Heuer) are rated for 200m, and there is no since in making such a watch with any less of a rating for sales competitiveness. Anyway, the Omatic is pretty cool watch, and it is priced right in between the quartz Seamasters and the automatic Seamasters.