Finnsub BANG review

I love UK diving. Coral reefs, crystal seas, and gin-clear waters… ok let’s not kid ourselves – it’s often cold and gloomy (at best), meaning a good dive light is pretty essential kit.

The good news is there is a range of lights on the market to suit everyone from beginner to professional. The bad news is they all have one thing in common: electronics. And wires. And batteries. Ok, technically that’s three things. And all of which don’t respond well to being immersed in water for long periods.

How do you turn the BANG light on? The clue is in the name

However, Czech tech equipment manufacturer Finnsub might have hit upon the solution. Meet the BANG light. Yes it’s small, Yes it’s stylish. And importantly, it is milled from a solid delrin body with no external switches or joins to allow the corrosive effects of seawater to do their work.

Pretty neat huh – but how do you turn it on? The clue is in the name – you tap, or ‘BANG’ the light gently three times. At this setting, it’s putting out 366 lumens and will burn for 10 hours.

Tap the torch twice more, and it now emits 1100 lumens for a maximum time of two hours.

Two versions are available, either a five-degree spot beam with black head, or a wide beam like this one offering 10 degrees or arc, which has a fetching orange head. These grooves act as a heat sink to prevent the torch overheating, which the built in software should prevent anyway with an automatic cut-off if it reaches 60 degrees centigrade.

The light source is CREE LEDs connected to a lithium-ion battery good for 2000 cycles. With no way for water to get inside, Finnsub opted to make these external contacts magnetic, thus connecting simply to the charger.

In addition, the BANG light comes with a soft ‘goodman’ style handle to wear on the back of your hand, and a rather fetching drybag to keep all the different elements together.

On dive day the BANG takes a bit of getting used to the first few times, with an accelerometer inside that is programmed to identify a deliberate BANG, BANG, BANG, as opposed to say knocks in the boot of a moving car. Like the best things in life timing is everything, and by finding a rhythm of between 0.3 and 0.8 seconds will power up the light. BANG BANG again switches up the power, and three more shuts it off again.

Once you’re used to it, this movement becomes second nature – and is certainly easy to do when wearing thick gloves or bulky equipment.

Finnsub says the battery is good for approximately 600 full-to-empty recharges, which in reality would likely take ten years if you use and half-empty it every few days. So this is not a toy and will go the distance. Likewise the BANG light is waterproof for depths of up to 100 metres, meaning it should illuminate some truly gloomy places if you choose to take it there.

The Finnsub BANG is an innovative dive light priced under £400 that could work as a backup or a primary for most UK divers. Now I just need to work on my BANGING technique…