Recently, while cleaning out my closet, I discovered an old friend, one of my old regulators that had seen me through some great early days of diving. This dusty relic was in sore shape, dented by years of use and showing the signs of recent neglect. Nearby sat one of my newer regulators and when I compared the two, I couldn't help realizing just how far dive gear has progressed over the years. My old reg was made of metal and seemed very heavy compared to today's regulators which utilize space age plastics in their construction making them light as well as tough. Improvements in the internal engineering have also made today's regs more reliable and easier breathing.
The latest in the long line of high quality regulators from Scubapro is the D400-Mk 5 combination. I recently had the opportunity to try this regulator and was pleasantly surprised by its ease of breathability. Identical in looks to the D350, the differences of the D400 lie within the futuristic looking housing. The fibreglass-reinforced polyester casing makes this regulator very light and comfortable and corrosion resistant. The lower, exhaust portion of the D400 is surrounded by a moulded rubber cover that protects it from damage and also enabled me to purge the regulator easily, even with heavy gloves on.
On the front of the D400 is a Dive/Pre Dive control. I like this feature because it reduces the possibility of the regulator free flowing while entering or leaving the water. When in the Pre Dive position, a booster spring comes into position behind the lever to stiffen the valve mechanism and when it' s time to descend, a flick of the switch into the Dive position, retracts the booster spring, allowing unrestricted performance.
The premiere difference of the D400 is increased air flow. The D350 had an air flow rating of 32 standard cubic feet per minute, (SCFM). The technology behind the D400 has bumped this up to 40 SCFM. This difference has been achieved by increasing the distance that the poppet lifts away from the orifice. This mechanical advantage is accomplished by means of leverage, by creating a flat surface in the round cross section of the demand lever. The demand lever in the D400 is also 25% larger in diameter than in the D350 and this added thickness creates the improved lift.
At the heart of the D400 is its unique, pneumatically balanced demand valve with downstream override. For those of you who speak Greek, this probably makes perfect sense, but for those of us who don't, it refers to the fact that the opening and closing action of the valve utilizes almost equal air pressure on both sides of the poppet, creating a balanced condition. Downstream override comes into play because of the slight pressure bias towards the downstream side of the poppet which will tend to open the valve in the case of any over-pressurization.
The Mkl5 first stage contains two high pressure ports and five low pressure ports. Four of the low pressure ports are arranged around 180 degrees of the circumference and one comes directly off the end of the cap. Inside the Mk15 first stage is an air balanced flow-through piston, a hallmark of Scubapro regulators since the mid '60s. The stainless steel piston in the Mk15 is supported by a high density plastic bushing system which ensures that it never touches metal when it moves. The bushing provides extremely tight tolerances without impeding piston movement. The Mkl5 has also been fitted with a thermal insulation bushing that deters ice formation on the piston and spring. The Mk15 can be modified to a DIN fitting and a kit is available to upgrade it to 4350 psi. All this comes in a housing with a satin chrome finish which ensures that this regulator looks as good as it works.
If I had to pick one piece of dive gear that has really revolutionized the way we dive, it would have to be the dive computer. Over the years computers have proven their reliability and are now found in a variety of designs, another example of just how far diving and dive gear has advanced. There was a time when planning a dive, and especially a repetitive dive, involved sitting down with a set of dive tables and twisting your brain through a series of computations to ensure a safe dive. Now, with dive computers, we can plan our dives at the touch of a button and also monitor the dive limits while we are at depth. What a concept!
Computers are divided into two basic styles, air-integrated and non air-integrated. Scubapro has now unveiled their first air-integrated dive computer. The TRAC (stands for Time Remaining Air Computer) is basically the air-integrated version of the new DC-12 dive computer.
Turning on the computer is a simple matter of touching two metal contacts with moistened fingertips which starts the com puter scrolling through a series of function or modes. When the desired mode appears touching the contacts again will stop the~ scrolling and allow you to access that mode Unlike many other computers that cycle two screens to give total dive information, the TRAC gives you everything you want to know on one screen at the same time. All this information is divided into separate compartments and displayed on a large easy-to-read screen.
The DC-12 indicates the ATR (Air Time Remaining) in minutes for the remaining air in the tank at the present depth. As a safety factor the TRAC calculates your ATR with a reserve of 450 PSI, plus the air required for a safe ascent. As well as being displayed numerically, the ATR is also represented as a bar graph. The no-decompression time/ total ascent time is shown opposite the ATR and being able to see these two figures at the same time allows an intermediate comparison which is important for safe dive management. Tank pressure is shown digitally in the lower part of the display and updated every 15 seconds. A LOW AIR warning appears if the pressure falls below 750 PSI.
When a dive enters a decompression phase, the no-decompression time displayed at the lower left, now shows the total time needed for ascent and a decompression stop ceiling is given in the top left. A bar with the word DECO will also flash just above the depth reading in the centre of the screen.
The TRAC is powered by a factory replaceable lithium battery that will last for about 14 years at a rate of 75 dives a year or nine years at a rate of 200 dives a year. The memory of the computer will log your last six dives in detail and the log mode can be accessed immediately after a dive. There is also a permanent record log which records maximum depth attained, total number of dives and total hours logged. Altitude settings for the TRAC are user-adjustable after 2300 feet. Between the altitudes of 11,000 and 14,000 feet the TRAC will only measure depth and time. A sturdy rubber case protects the computer from damage.
In addition to the instruction manual, an informative video comes with every unit.