If you want something that LOOKS like a complicated diver’s watch - this is the one for you. Just don’t mistake it for an ACTUAL diver’s watch. It does NOT have a helium release valve, and it cannot be read underwater in the dark. For more information on what is a REAL diver’s watch, see the “Diving Watch” article in Wikipedia.
It does look good, a result of the Italian attention to detail in styling. The timekeeping function does not meet the standards for a chronometer, but then the manufacturer doesn’t SAY it is a chronometer, but a chronograph – not the same thing.
I subjected mine to a time keeping test. Over Twenty-One days it lost four seconds. Not particularly bad, but not up to the standards of a Swiss quartz chronometer (a different standard than for a Swiss mechanical chronometer), which over the same 21 day time period, would be +/- 1.47 second.
The standard for a quartz chronometer watch, which is set by the Swiss Official Chronometer Testing Institute, known by its French acronym of C.O.S.C. (Contrôle Officiel Suisse des Chronomètres) is +/- 0.07 second per day at 23 degrees Celsius (73.4 degrees Fahrenheit)
The earlier review was correct, the luminous dial does not hold its brightness for long, and there is no backlight. If you want to know the time in the middle of the night (or underwater), you will need to turn a light on.
I did another test. Using a 650 lumen Fenix TK22 flashlight on turbo setting (bright enough to burn your retina in a few seconds), I placed the head of the flashlight over the dial and engaged the light for 1 second. I was able to read the dial eight minutes later, but just barely. The second hand, the 24 hour hand, and the stop watch minute counter could not be seen at all.
When the dial is exposed to fairly bright office light for several hours and then taken into a dark room, the dial can be read, although not that well, at the 1, 2, 4, 5, 7, 8, 10, 11, and 12 o’clock positions. I could barely see the three o’clock position, and could not see the six and nine o’clock positions at all. The second hand, the 24 hour hand, and the stop watch minute counter could not be seen at all. This degree of luminescence fades quite quickly.
The bezel does not rotate, so it cannot be used for any sort of calculation, as a true diver’s watch can. The name of the watch - Marine Shark Master - IMPLIES that it might be a diver’s watch, but it isn’t. A true contemporary diver's watch is manufactured in accordance with the ISO 6425 standard.
Also, don’t be fooled by the listed retail price of $500.00. On the day I wrote this review, the watch could be purchased from Amazon for $118.73.
In short, if you want a cool looking watch – buy this one. Just don’t expect it to be what it appears to be – a real diver’s watch.