All Rolex Submariner models before the 5512, such as: 6204, 6200, 6538, 5508, 6536 and 6536-1 were all Submariners with no crown guards,making them recognizable by their big or small crowns. The Submariner 5512 is important in Rolex history as it was the first Rolex with crown guards.
FIRST GENERATION: Launched in 1959. The peculiarity of this generation is that had square crown guards, Its movement 1570 with Gloss black dial, Gilt, Chapter Ring, and an Oyster bracelet.
SECOND GENERATION: Launched early 1960s.This generation was distinguish by its pointed crown guards. Some of its features were: Movement 1560/30, Gloss black dial, Glit, Chapter Ring, with an Oyster bracelet as well.
THIRD GENERATION: launched in mid-1960s. It also had pointed crown guards, Movement 1560, Gloss black dial, Glit, 4 line and the Oyster bracelet.
FOURTH GENERATION: Launched in the late 1960s. It had normal crown guards, its movement 1560, Non gloss dial, White printing, and Oyster bracelet.