Reference 6204, the very first Submariner, was introduced at the 1954 Basel Fair, production had however already begun in 1953, year of production of the present example. Perhaps the rarest variant of the early Submariner ref. 6204 distinguished by the designation “Sub-Aqua” to the lower half of the dial. To date, less than five examples of this ultra-rare variant are believed to have appeared at public auction.
Although the origin of the name "Sub-Aqua" is unknown it is generally thought that the model was made by special order for the British Sub-Aqua Club or BSAC, one of the most famous recreational diving clubs of the period. The club was founded in 1953, the year of the development of the very early Submariners for this particular use.
The present “Sub-Aqua” still features the slim "pencil" hands and the distinctive sweep centre seconds hand known as "lollipop hand", easily recognizable by its large luminous dot at the tip without the pointed extension. The bezel is the original version without graduation for the first fifteen minutes, the crown the correct type and the bracelet is from the same period, stamped 3.54 and made by the celebrated Gay Frère of Geneva, suppliers of high quality bracelets for Switzerland’s most celebrated watch manufacturers.