The new Deep Blue Daynight T-100 Tritium Flat Tubes is not particularly handsome in broad daylight, but it shines like a Christmas tree in total darkness. What more would you like from an affordable diving tool that is also rugged enough to withstand some real abuse serving as a daily beater for a person who prefers an active lifestyle to a miserable life of a couch potato?
Although the general public cannot imagine a diving companion without its hands and hour markers covered with thick layers of Superluminova or Lumibrite, the non-radioactive luminous mixture of Strontium Aluminate Oxide and Europium is definitely not a substance of choice when it comes to making a real “tool watch.”
The reason is simple: Superluminova isn’t particularly bright and its dim glow tends to fade away fast if it wasn’t “recharged” for some time under an ultraviolet lamp.
There is still a nice alternative to Superluminova, though, which is called “tritium illumination.”
Thanks to a process of radioluminescence (the radioactive tritium emits electrons that interact with a layer of phosphor material applied to walls of a tiny tube thus producing a bright glow,) tritium tubes do not need recharging and can glow virtually for years even if kept in total darkness.
Of course, after Chernobyl, Fukushima, and other nuclear accidents of smaller magnitude, people tend to stay away from anything “radioactive,” but let the word doesn’t scare you away when it comes to watches.
Until you break the tiny tubes and inhale the gas, you are absolutely safe from radioactive poisoning. In fact, the radon gas that constantly seeps into the basement of your house and fills your bathroom is a lot more dangerous for your health than a dozen of gas-filled microtubes.
Which brings me neatly to the new Deep Blue Daynight T-100 Tritium Flat Tubes diver.
Rated for depths of down to 300 meters, the Daynight T-100 comes equipped with 19 tritium tubes, 16 of which -the one that works as hour markers- are “flat” and the other three are normal cylinders that are installed into the hour, minute and seconds hands.
To increase the timekeeper’s legibility, Deep Blue filled “normal” hour markers with blue phosphor substance, while the tubes inside the hands and at 12 o’clock glow in yellow.
The coin-edged bezel with the standard diving scale is also luminous. However, since it is technologically impossible (or, at least, cost-prohibitive) to make the tiny tubes shaped as Arabic numerals, the scale is painted in bright green Superluminova that looks almost white in daylight.
Delivered in a 44 millimeter (52 millimeters lug to lug) stainless steel case, the watch is powered by the well-known ETA 2824 automatic movement.
Since the case is equipped with a solid back, the movement comes without any additional decoration, which is just as well, since it allows to somehow cut the costs of making this beautiful tool.
Speaking of costs, I must notice that the gadget is available right now at Deep Blue’s web site at an attractive price of just below $700.
Photos: Deep Blue Price: $699 (shipping expenses not included) Yep, this is me. Just had my beard trimmed. I am a founding father of this weblog since 2008. Bought my first mechanical watch in 1986 and it took me ten more years to realize that I have a problem: at some point in time watches became my passion. Well, it could be worse. 
Deep Blue Daynight T-100 Tritium Flat Tubes specification
Movement: Automatic, caliber ETA 2824, 25 jewels, 28,800 vph, Swiss Made
Movement decoration: Standard finish
Functions: Hours, minutes, seconds, date
Power reserve: 42 hours
Case: Stainless steel
Shape: Tonneau
Bezel shape: Round
Size: 44.00 mm (52.00 mm lug to lug)
Lug width: 24 mm
Dial: Black / Blue / Orange
Numerals: Luminous hour-markers with tritium flat tubes
Hands: Luminous, tritium tubes
Water resistance: 300 meters
Strap: Stainless steel bracelet with deployant clasp and wetsuit extension
Crystal: Sapphire
Back: Solid, stamped with Deep Blue logo