Close to home
Looking at a Rolex in an AD's window never did it for me; usually the AD was keen on placing the diamond-studded versions of the Datejust and TT (two-tone) GMTs and Submariner Dates and the occasional Milgauss. Being the complications fan that I am didn't help much either, with the Daytona (again in TT...) not really drawing my attention away from the multitude of competition. A shame really, when I consider the fact that my own grandfather worked in their Genève manufacture for over 25 years... .
click-the-pics for hi-res goodness
It was my fairly recent interest in the "Tool Watch" that slowly turned things around. Panerai, despite its not-so-tool-watch appearance, was my bridge to Rolex. My good friend Charles got me addicted to those 44~47mm cases and soon after, I had my first PAM. Not long after he surprised me, saying he wanted to go back to concentrating his resources on Rolex.. When I mumbled something like what the heck for, he showed my a photo of a 5514 COMEX. Then he showed me a 5517 "military" with its one circled "T" on the dial. Then an angled-shot of a 1665's T-39 Superdome... . That's when I understood that Rolex had a rich tool-watch history, beyond the diamonds and shiny TT cases... .
Saturation-Diver ... Sea-Dweller
Oyster Perpetual Professional. At least that's the group-name Rolex uses for their sports/technical models, such as the Explorer(s), Daytona, Deepsea, GMT, Milgauss, Submariner and Yacht-Master lines. My own interest however, quickly narrowed down to the Submariner and closely-related Sea-Dweller (SD) models. Although the Submariner's history is long and rich, I found the Sea-Dweller's shorter but just as exciting story to be most captivating. There's a ton of excellent information available on the 'net documented by people with vastly more experience than me so I will only mention some highlights here...
1665 - The first "official" Sea Dweller, released in 1971, came into existence after saturation-diving incidents where the french professional diving company COMEX and the U.S. Navy's Sea-Lab team discovered the adverse effects of helium during the decompression phases following a saturation dive. Thus the birth of the Sea Dweller and its gas escape valve* (aka HEV since Helium is the gas used in saturation diving). The 1665 was rated to 2000ft/610m which was roughly three times the rating of  production Submariners (660ft/200m) of the same period. The 1665 model includes the famous "DRSD" or double-red which had the lines Sea-Dweller and Submariner 2000 in red. Rolex eventually stopped using red print and the all-white lettered SDs received the nickname Great white. As a side note, prototype Sea-Dwellers (aka "single red" / SRSD) were produced around 1967, rated to 1650ft/500m and The COMEX-only 5514 version of the 5513 Submariner were fitted with HEVs.
*In order to provide full disclosure, it has been noted that Rolex partnered with DOXA to produce the one-way, escape valve solution and DOXA was first-to-market with their SUB300T (~1969).
The 1665 was superseded in ~1978 by the 16660 (aka triple-six) and some years after by the 16600. The model# change was to signify the move from the 3035 to the 3135 movement. Both had the newer gloss dials with white-gold marker-surrounds (apart from what I assume to be the remainder of 1665's matte dials used with the first batches of 16660s). The case of the 16600 was slightly altered, perhaps to support the new movement. Any other potential differences are unclear to me. The new generation of the Sea Dweller brought about even greater depth-ratings thanks to changes in the case, the replacement of the 1665's plexi with a thick sapphire crystal as well as a notably larger escape valve. These innovations provided the Sea Dweller with an impressive 4000ft/1220m depth rating! The next-gen Submariners, in comparison, managed an increase to 1000ft/300m with the migration to sapphire, improved Triplock crown, etc. Aside from the amazing depth certification, the Sea Dweller also benefited from solid end-links (SEL) and a bracelet with solid center links. Compared to the Submariner's tuna-can hollow links, the SEL & robust bracelet were a considerable improvement. To many a Sea-Dweller fan's dismay, the Sea Dweller was replaced by the Deepsea (DSSD). While the DSSD is an impressive feat of technology as well as an important tribute to Rolex history, it is quite a different animal. As such, many SD fans would have loved to see it released as an independent model and not as the SD's successor... .
16600 - SWISS - Lug Holes
Like most watches of the period, Rolex used tritium paint for their dial-markings and hands. Eventually they made the move to [Super-]LumiNova - just as all other companies did - to avoid the potential dangers inherit to radioactive materials like Radium and its successor Tritium. The 16600 was one of the models that went through the change. Up to roughly 1997~98, they had tritium dials, marked by the industry-standard SWISS-T < 25 just below the 6 o'clock marker. In 1998, Rolex made the transition to [Super-]LumiNova by changing the dial lettering from SWISS-T<25 to SWISS. Not long after (late '99 or early 2000) they changed the label to Swiss Made for reasons beyond my knowledge. Other companies use L Swiss L or even L Swiss made L but all these variations refer to modern [Super-]LumiNova-painted dials/hands (and of course the fact that the watches are manufactured in Switzerland). After reviewing the various Sea Dwellers available, I decided on a [Super-]LumiNova dial and lug-holes (the SD "loosing" its lug-holes with the F-serial 2004 model). I managed to find two units that fit my requirements, a 1999 A-serial SWISS and a 2003 Y-serial Swiss made dial. Both seemingly in the same condition, I went with the SWISS dial as it is a bit more unique.
The look and feel that is Rolex
Having been wearing larger and heavier watches, I was concerned that the SD might come across somewhat ...lacking, but it was quite the contrary. Not only does the SD, with it's 143g and robust stature compete with my 144g 44mm PAM, but the iconic Rolex tool-watch design demands the wearer's attention. The dial, the hands, the bezel and insert, the lugs, crown-guard and crown itself all come together in perfect harmony - no feature is overwhelming, no feature expendable. Add to that the HEV which emotionally serves to remind the wearer of the rich history Rolex has with professional diving. While I enjoy using a myriad of straps with my Panerai, the SD is not restricted to being worn on its bracelet (albeit a nice bracelet at that). With the help of so-called NATO straps, the SD achieves that rugged look associated with the military. Recent hi-quality rubber straps have also provided the SD with a new look.
Looking past form is naturally function; the fact that the 16600 SD is powered by the C.O.S.C.-certified 3135, one of the most dependable Rolex movements ever built, completes the package and makes this my perfect first Rolex.