I have to correct a few points Bruce has made about the original Submarine watch in this post.
Slightly moot but, it was never known as the Submarine Commanders watch, simply the “Submarine” Watch.
The Royal Navy representatives he mentions were not acting as representatives of the Royal Navy and did not approach Tavannes; the story goes that 2 off duty, Submarine commanders approached Brook & Son in Edinburgh who subsequently chose Tavannes as their manufacturer, this is important.
As the pictures of the watch prove, the Submarine watch was available from 1915, so 11 years before the Rolex oyster watch.
Bruce also mentions the watch was exported to several retailers and wholesalers in the UK, this is completely wrong and quite misleading as Brook & Son in Edinburgh had exclusive rights of sale for 5 years, from 1915 to 1920, meaning the only place you could buy this watch was from them, they were the sole retailer of their Submarine watch.