Tudor introduced the distinctive Snowflake handset in its 1969 catalog, with the references 7016 and 7021. Accordingly, the indexes on the dial took the square shape you see here, which differentiated this Sub even more from its Rolex-born siblings. A few other design peculiarities further set the Tudor Submariner apart, including the existence of a blue configuration and for the version with date, a lower magnification and a different font for the date disc. The following generation, the references 9401/0 and 9411/0, luckily kept these unique attributes, which explains the popularity they now enjoy. It might have looked different than a Rolex Submariner (and be priced lower), but it was no less tough, explaining why the French Marine Nationale trusted these diving watches for more than 20 years.