The red letter Submariner was the first Rolex Submariner to be released with a date function at the 3 o'clock position and utilising a 'cyclops' to magnify the date. There were 7 different versions and production went on until about 1975 when the red lettering was dropped and all white lettered dials continued from then on.
The first 3 versions are classed as 'metres first' as the 200m comes before the 660ft and are the most desireable and collectible - a couple of these versions also turn a stunning brown colour and get called 'tropicals'.
From the end of 1970 the wording changes to 660ft=200m on all watches...
The date window Rolex Submariner with cyclops is probably the iconic watch that people recognise Rolex by around the world. A bit like 911's they have evolved over the years but not changed a huge deal!
![Image](https://scontent-lhr3-1.xx.fbcdn.net/hphotos-xap1/v/t1.0-9/12509348_10153362447628603_4808809153500520905_n.jpg?oh=f93409402bfa2d8fd5c2ac7b5c1c3c70&oe=57496B28)