Scubapro G500 and MK 20 Ultralight

Like most divers, when travelling to far flung destinations in order to satisfy my nitrogen habit, I usually take along as much of my own dive gear as possible, especially a regulator. I like my own gear, I'm comfortable with it and I know where it's been. I also know how it has been cared for and in the past I have been disappointed on occasion by some of the rental gear I have used in remote areas. The only difficulty with carrying all your own gear is that it adds considerably to the weight and bulk of your luggage and seriously impacts your popularity at the luggage check-in counter. But now Scubapro is out to help us with some of our overweight baggage woes by introducing the first lightweight regulator with the Mk 20 Ultralight (UL) version.

The standard MK 20 first stage has been a benchmark of Scubapro quality, durability and precision for the past two years. This pneumatically balanced, flow-through piston first stage includes many state of the art design and machining techniques that ensure high performance under even the harshest of conditions. The inside of the first stage of any regulator is a rather intense place, mechanisms must perform to precise specifications under extreme pressures. The excellent performance of the Mk 20 revolves around the precise alignment of the piston with the high pressure seat, a key to the efficiency of any regulator. In addition, the large-bore piston has a rounded sealing edge which prevents scoring of the high pressure seat, which in the case of the MK 20 is concave and made from a harder material. These factors work together to increase the overall efficiency of the Mk 20 and the longevity of the high pressure seat. This allows the reg to remain at peak performance throughout the service period. The resulting reduced wear and improved sealing ensures an extremely steady intermediate pressure and smooth air delivery, regardless of the tank pressure.

The possibility of freezing in the Mk 20 has been minimized thanks to the thermally insulating bushing between the piston and spring which keeps the spring isolated from the piston end, which gets very cold due to rapid air expansion. The main spring is also coated in polyurethane to stop formation of ice. And the MK 20's two high pressure and five low pressure ports ensure ample connection points for any accessory.

The only drawback to the MK 20, and for that matter, just about every other first stage on the market, is the weight. Nearly all first stages are made of chrome-plated brass and are heavy, weighing in at about two pounds or more. This poses no problem when diving close to home but when it comes to travelling abroad and airline weight restrictions, every ounce counts. And that is where the MK 20 Ultralight (UL) comes in handy.

The Mk 20 UL offers the same performance characteristics as its heavier cousin and is identical in design and engineering except that all components, including the piston, are made of aluminium alloy. Subsequently, the MK 20 UL weighs in at only 13 ounces! But don't let its light weight fool you, the MK 20 UL is very durable and can be used in any application where weight is a concern. The housing of the MK 20 is coated in a slate-grey ultra-hard ceramic which is harder than chrome and impervious to electrolytic corrosion. The Mk 20 UL is available in a 3000 psi yoke version or a 4350 psi DIN version.

The logical complement to the Mk 20 is the G500, Scubapro's newest, smallest and lightest second stage. The G500 is 15% smaller than the G250 and has an air balanced linear flow valve and diver adjustable VIVA flow assist. An anti-set poppet prevents air leaks and helps keep the second stage at peak performance longer. A high-travel lever and diaphragm improves performance at extreme depths by 25% and a Delrin sleeve surrounding the second stage inlet tube prevents freezing. The controls are easily manipulated, even while wearing heavy gloves and the small size and weight help to reduces jaw fatigue. The G500 has a soft purge button and an anti-surge diaphragm which prevents it from cycling when swimming into a current.

In the past several months of use, in a variety of cold water conditions from the Pacific to the Atlantic in depths to over 50 metres, the Mk 20 UL/G 500 combination has performed very well.

Now if someone can only come up with an ultralight weight belt.