;) Difference between Scubapro S600 , G250 and A700 second stages

Hello All ,

Could anyone tell me the difference between the Scubapro S600 , G250 and A700 , they are all balanced with VIVA Venturi knob and breathing resistance adjustment. So what's the difference and what makes any of them better than the other ?

Best Regards
Nomro

The s600 and g250V have very similar internal parts and flow vanes, the major differences are:

1. Larger case and diaphragm on the G250V
2. Metal air barrel on the G250V (although the latest S600s will have a metal air

The A700 has an all metal case and an axial flow vane similar to the design used in the X650.

All three breathe very well and the metal case of the A700 reduces dry mouth and improves cold water reliability. The metal air barrel and larger diaphragm of the G250V give it superb performance and it has been the workhorse of technical diving since the original G250 was introduced in the mid 1980s. Scubapro brought the design back as the G250V in part due to strong demand for older used G250s in preference to the G250HP that replaced it.

The S600 is more compact, and breathes very well, but loses out in terms of cold water performance to the other two, although a metal air barrel will help.

The correct answer as to which one breathes best is "yes" . Unless you have ultra sensitive testing equipment there will be little difference noted between them.
For me the deciding factor would be "will I be diving really cold water" (I mean below 43 degrees F). If so, then I would be more concerned about the 1st stage (mk 17 for better cold water performance) and maybe give an edge to the 700 and G250V (though the metal barrel in the newer 600s will help).