5712 vs 3712 the differences - part 1 - "the production numbers". The 3712 was produced in 2005 and it had a short life, it was discountinued after just one year or a little more. In 2006 was introduced the 5712 for celebrating the 30th anniversary of the first Nautilus (ref. 3700) and after more than 10 years it is still in production. My assumptions (based on statistical calculations on a large amount of data ) lead me to think of a number of 7-800 units for the 3712 and of 4-5000 units for the 5712 (and still counting). Among this 7-800 ref. 3712/01A we will find a first and a second series (we'll talk about that) Obviously these are only assumptions but the owner of the absolute truth can only be Patek Philippe itself. If someone has got some different numbers is very welcome.