Appeared in DIVER March 2008

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John John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.

REGULATOR SCUBAPRO MK17 G250V

YOU KNOW HOW IT IS. You buy something that does a good job, and youre really happy with it. It may be a car or washing machine or some other consumer durable - or even a diving regulator.
You use it satisfactorily for years, until it reaches the evening of its life. You would gladly replace it with an identical model if you could - only you cant. Its been improved.
Its now loaded down with features you didnt want. It has value-added as the salesman will gleefully tell you, or more things to go wrong, as you might prefer to put it.
I bought my first Scubapro G250 regulator in the mid-80s. It served me well for years and
I gave it to a diving club, which Ill bet is still using it.
I wouldnt say it was an unbreakable design, and, combined with a piston first stage, it gave me a couple of frights on cold freshwater dives midwinter. However, had I only ever used it in the warmer seas of the UK, I would probably have sworn by it rather than swearing at it.
I am aware that there are many divers worldwide who have had years of confidence-building use out of their G250 and are reluctant to change.
Well, the marketing men at Scubapro know this too, so they have reintroduced the G250 in a new guise. They call it the V for Vintage style.

First stage
For years Scubapro backed its fortunes on a range of piston-type regulators. I know that
its old designer Roberto, long retired now, constantly nagged the company to let him design a diaphragm-type regulator too, but no one above him wanted to know about it.
Scubapro was known for high-performance piston regulators, and that was that.
So, just before he retired, Roberto went ahead and made a diaphragm reg anyway. The MK17 first stage is the direct descendant of it, and a jolly fine item of kit it is. Wherever you are now, Roberto, enjoying your retirement, I hope you relish the knowledge that you were right!
The MK17 is an environmentally sealed design that has a massively finned styling to increase its heat-exchanging properties, and to prevent any ice that may form from creeping up to where it matters.
It has a massive potential maximum flow-rate, so there will always be enough supply whatever the depth, and there is little chance of me arriving at the surface in Stoney Cove in a cloud of bubbles and expletives during a winter dive.
It has four medium-pressure and two high-pressure ports, well spaced for convenient hose routes, and a computer transmitter.

Second stage
The G250V second stage also has a lot of metal in it, for good heat-exchange properties and resistance to freezing. This includes a metal inlet tube, orifice and hose-connector locking nut, and goes right through to the BRA knob.
With the trend being towards smaller and smaller second stages, this one looks enormous, but I guess its what we used to use.
It has a much bigger venturi predive/dive switch than some contemporary Scubapro second stages, and the cracking-pressure adjustment knob (or BRA) is similarly easy to use with a gloved hand.
The whole thing is made to be very robust. Whats not metal is made of nylon reinforced with glass fibre. Both the pressure-sensing diaphragm and the exhaust valve are made from a new single-compound silicone, which gives better consistency in manufacture, and better dimensional stability and flexibility.
The front cover screws on and overlaps the main case, so there is little chance of distortion in the harsh environment of a club RIB or liveaboard aft deck.

Purge Control
This is as big as it was in the 1988 version, but its easier to locate in a hurry because a big metal ring surrounds it. The purge is very effective, but it is progressive enough not to frighten a trainee diver.

Comfort
Im told that the performance of this modern G250V is 35% up on the original. Im inclined to believe this. Its amazing how low our expectations of regulator breathing performance were only 20 years ago.
Because the front cover of the second stage is so large there are some very big holes, giving plenty of opportunity for water to flow through to the pressure-sensing diaphragm. This really does help to give a quick response to depth changes, and ease of breathing.
Combine this with the massive airflow possible with the MK17 first stage and this regulator compared very favourably on one side of a set of twin tanks to what I had until then thought of as the best-performing regulator I had ever used. Only the mouthpiece was less than kind.

COMPARABLE REGULATORS TO CONSIDER:
Apeks XTX50 £350
Mares 42 Abyss £370
AquaLung Legend Supreme £325



Divernet Divernet
SPECS
SCUBAPRO MK17 G250V

PRICE £339
FIRST STAGE Sealed diaphragm
PORTS 4mp, 2hp
SECOND STAGE ADJUSTMENTS Venturi plus/minus and BRA
CONTACT www.scubapro-uwatec.com
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