Launched in the late 1980s, the reference 16600 is virtually identical to the late “Triple Six,” maintaining its sapphire crystal and its 1,220 meter water resistance. Over its remarkably long production period, the luminous material evolved from tritium to Luminova, and then to SuperLuminova. You can easily tell which is which by looking at the bottom of the dial – T Swiss T<25 indicates Tritium, Swiss indicates Luminova, and Swiss Made indicates SuperLuminova. Not too tough, right?
The reference 16600 also utilizes the caliber 3135, a slightly improved version of the caliber 3035. It has a longer power reserve and a full-fledged balance bridge, instead of the balance cock. The reference 16600 was discontinued after 20 years in Rolex catalogs, making it the longest lasting Sea-Dweller reference, and an easy model to find pre-owned. As with modern watches, a full set (with original box and papers) is preferable to a “naked” watch, even if it means paying a small premium (in the case of vintage watches, this premium can be drastically higher given the considerable time since the production of the piece).