However, without a military budget to use to purchase one, and without a military transport corps to see it to the dive site, a Metalsub lamp can be a little impractical.
Now the company has come up with a lamp that I found to be no imposition to slip into my dive bag at the last moment before setting off on a long-haul flight.
At around 24cm long, its the Bren-gun-carrier version of the heavier artillery in the Metalsub armoury, and is said to be good for 240m, though I didnt test this. Its called the XRE700.

Power Source
The latest lithium-manganese battery is used to power this baby. Its compact, but packs enough punch to deliver 7.2V over 110 minutes, when the lamp is used at full power. At one-third power, the manufacturer claims that it will burn for more than three hours on a full charge.
A mechanical thermal-protection device is fitted to prevent over-heating, and an over-pressure valve allows any gases that might build up during charging to escape. The lamp is also protected from the deep discharge resulting from being inadvertently left switched on.
I like the way it can be recharged via two external plugs, so there is no reason to break
it open and risk flooding it through incorrect re-assembly. Thats vital, because the one thing a lithium-manganese battery doesnt like is sea-water. Get it wet at your peril.

Light Source
The XRE700 uses three 4W LEDs to pump out an enormous amount of light in a cone that equates to a useful spot. An LED indicator at the back of the lamp glows green during charging, but otherwise indicates the state of charge of the battery during use.
Green means that more than half of the burntime is left, whereas orange means it could be as little as one fifth.
Red means that its on the last 20% or less, and flashing red that light output will be reduced to one-third, and you have 10 minutes left before it fails.
This all holds true in tropical waters, but in very cold conditions I found that it went from green to orange almost immediately.

Trust Metalsub to come up with something more than just a switch. You turn this torch on by pushing in the big switch at the rear of the body and twisting it through 90° for full power, or 45° for one-third power. This push-in operates as an effective safety lock.
By manipulating the switch between the two on positions, you can get various other effects in sequence, such as a rapid strobe setting when it flashes four times a second, or a beacon flash at only once a second.
If you want to send a specific message, such as when youve been drifting without being picked up for a day and a night, it will also signal SOS.

This has a useful tight spot at the centre of its very bright beam, but a wide and bright peripheral halo too, so as well as seeing what youre looking at clearly, youre also very aware of what is not directly in the centre of the beam. The one-third power setting is frankly bright enough.

Oceanic OP33, £189
Kowalski LED, £180
Dive Rite LED 500, £350
Scubapro Phad 8, £359

PRICE £319
BATTERY Lithium Manganese
BURNTIME 110 minutes at full power
CHARGING External via two plugs & intelligent charger
SWITCH Five-mode magnetic
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