The early Rolex submariners consist of the early 6500, 6504, 6536, 6538, 5508 and 5510 followed by the 5512 an 5513. The Rolex 1680 submariner was the first subs that come with the date. It was not the first Rolex Sports watch to carry a date, this honour arguably goes to the Rolex GMT Master, Model Ref 6542
There are 2 versions of the 1680: mark 1 using cal 1556 and mark 2 using 1570 and the Ref 1680 weres produced from 1969-1978- 80. The 1680 series has a special dial using red SUBMARINER.
Within this 12 year period the Red Submariner is widely believed to be produced for the first 6 years, 1966-73. Many original Red Submariners have been serviced and as a result, many would have had their original red dials replaced with the standard white dials during the years making it quite rare to find the Red submariner.
As for the depth there are two versions one with the feet first while the other in meters depending on the region, I guess.The 1680 was succeed by the Ref 16680 using cal 3035, Ref 16610 using cal 3135.