Most dive watches have strong luminescence. However, some people looking for a dive watch are dissatisfied with its brightness. The main reason is that the glow duration is short; with Luminova, it typically lasts about 10 to 20 minutes.
Some may think,
“It fades in just a few minutes. Is it defective?“
“Why isn’t it brighter?”
I believe these complaints stem from a slight misunderstanding. The use of luminous paint in dive watches is primarily to ensure visibility after phosphorescence underwater. For instance, the SPG (Submersible Pressure Gauge), which indicates residual pressure in a diving air tank, is luminous.
Many divers use it at depths of up to 40m in tropical seas. During daytime recreational diving, there is virtually no need for glow-in-the-dark features since the air residual pressure gauge can be read with sunlight (excluding night dives).
Recreational divers typically dive for about 30 minutes; with some experience, they might stay underwater for about an hour, but few remain at depth for that long. Most dives occur in well-lit areas.
So, when is the luminous light useful?
It’s essential for night diving, in dark environments (like caves or caverns), or during deep dives. Usually, divers carry two or more lanterns during these dives. The purpose of the lanterns is not only to ensure visibility but also to illuminate the SPG and other luminous equipment (like analog dive watches and cave diving markers). The lantern briefly illuminates the luminous equipment to help read gauges or markers safely.
In conclusion, the function of a luminous dive watch isn’t to maintain a bright glow throughout the dive but to assist when needed, often in conjunction with a lantern. This can be confirmed through photoluminescence. Therefore, the duration of the glow isn’t critical.
So, please don’t be too concerned if your watch’s luminescent feature isn’t as bright or doesn’t last long!
