Originally made with a red luminous triangle at the midnight position, researchers instead change the colour to white, as red was detected to be the first colour to be absorbed underwater and lost easily. With a depth rating of 300m, it is definitely practical for the avid diver, where he can have access to accurate time in most situations. In 1979, the plexiglas crystal was swapped with the durable and scratch resistant synthetic sapphire crystal widely used today. An interesting point to note would be that Rolex released the 50-year commemorative model with a special green bezel and an enhanced dial in 2003.
Though seeming insignificant, the enhancements made in the anniversary model's dial should be looked into seriously as Rolex has put in an incredible amount of effort, investment and research into the designs of their watches, one good reason why there are many replicates and counterfeits of its watches. Rolex has included the maxi-dial in the anniversary edition of the Submariner, meaning that its hour markers are larger, with the widening of its minute hand, making it more obvious in the dark as more luminescent paint is used. Due to the success of the maxi dial innovation, it use would likely to be seen in other upcoming models created by Rolex.