The final module in the 7 month program is a three week Deep Dive course. This is where everything you’ve learned comes together. All the knowledge you’ve gathered from day 1 in physics and medicine, to the moment you step on the MV Response (DIT’s boat) now comes into play. You’re not doing very much that is new, you’re simply pulling it all together.
|Week 1||Familiarization with the boat, learning the recompression chamber and diving air system, vessel safety and equipment procedures. Then you’ll head out to Lake Washington and begin dives of 60 feet. This is where you will learn about Surface Decompression with the use of a chamber, and making the five minute surface interval time frame required.|
|Week 2||Diving to 130 feet for :35 minutes, with the use of surface decompression.|
|Week 3||Diving to 160 feet. Here you will need to perform a 1-4 minute decompression stop at 40 feet in the water column, in addition to surface decompression.|
How you’ll learn
In the deep dives module you’ll learn each thing one step at a time, and you’ll practice it over and over until you’re comfortable. Instructor Doug Irish explains, “With surface decompression diving we crawl, walk and then run. We train in baby steps.” You get used to doing surface decompression starting with dives where you don’t actually need it, so by the time you do need to use the Sur D procedure, it’s familiar and comfortable. “If someone isn’t getting something, we have them do the same thing day after day until they get comfortable with it. And that’s what it is all about, getting comfortable with it.” Says Doug.
Once you’ve got the shallower depths down, then you take what you’ve learned and start to travel to deeper depths. Instructor Mike Kleinfelder explains, “They travel to a different depth, but all the motions are the same. I remind them that they are diving where man is not meant to be. The key is to have them do it safely. Every time.”
By the middle of the second week, most students begin to really get the hang of it. “By the time they’ve done the 130, they are pretty much running the dives themselves; The instructors are just overseeing all safety factors, and answering questions.” Says Doug.
Watch: Surface Decompression
In this course you’ll use a hydraulic stage. Its speed is controlled by a supervisor on the boat. When you dive, you’ll be lowered and brought back up on this stage, which helps control travel rates while ascending and descending. This is widely used in the industry.
You also get to use hot water suits, which are awesome. These are used in the industry whenever divers are diving in colder water or are breathing a mixed gas (helum/air). Because helium is seven times more conductive in its properties, it will make the person breathing it colder than breathing straight air, so for the diver’s safety, to keep their body temperature up, they use a hot water suit.
“It’s like being in a hot tub, it’s very nice. I wish every dive could be in a hot water suit.” Says Instructor Mike Kleinfelder
Another new thing is controlling the diver’s oxygen supplies from the air systems manifold. This is the first module where you’ll have O2 capabilities.
The decompression chamber is a large pressure vessel that divers go in after they do a deep dive, and it allows their body to comfortably off gas nitrogen built up from the dive. You’ll learn how to use the chamber and all the parts of it, including BIBS, which stands for Built In Breathing System. It’s a hose that comes out of a manifold inside the chamber, with a face mask, so the diver in the chamber can breathe 100 percent O2 for decompression.
Surface decompression or SUR D, is the procedure that divers use to safely decompress in the controlled setting of the chamber on surface. Normally divers can off gas nitrogen during the ascent to surface, by remaining in the water at dictated depths and time. But by having the chamber on the vessel, the diver does not need to spend extra time in possibly cold and unstable water conditions, instead, they are able to fulfill their required decompression obligation in the controlled environment of a chamber.
With the SUR D procedure, each segment of the ascent is controlled and timed for safety. There’s three stages of time. It begins when you hit 40 feet on your ascent. You take 1 minute to get from 40 feet to the surface. Once you arrive at the surface, you have 3 minutes and 30 seconds for the undress phase, to get you out of all of your equipment and the suit. The last stage, is where the divers are pressed to 50 feet in the chamber at a rate of 100 feet per minute, this will take no longer than 30 seconds. You have a goal of 5 minutes to do all this. Instructor Mike Kleinfelder describes this as “the magic number”. Each step of the way you have a teammate supporting you to monitor your health and well being. With these depths and bottom times, you’re looking at close to an hour in the chamber to decompress.
When asked what it feels like to the instructor in those 5 minutes, Instructor Mike Klienfelder said, “It’s controlled chaos at that point. We practice it during the 60 foot dives, where it’s not yet required, but we do it as a dry run. So that once we are actually required to perform SUR D dives they are comfortable with the motions, the equipment, and the timing.”
Because there are risks associated with nitrogen intake and pressure related issues, all aspects of deep dives, particularly ascents, are closely monitored and regulated.
There are two instructors on the vessel at all times, one on the outer deck, and one on the inside monitoring communication devices and video feed from the divers.
If the communication devices fail, all divers are trained in simple line pull communication that has been relied on by divers since the beginning of surface supplied diving.
On most dives, two divers will descend on the stage, to just above the bottom of the lake bed. Here they may work on a basic project or practice their knot tying. A third diver will “hat-up” and respond to the divers as a ‘Stand-By Diver’. During the dive, the divers will descend to the bottom, or ‘mud line’ and walk a short distance to obtain the required depth. The diver performs a ‘bottom report’ and returns to the stage. It may not sound like much, but the effects of nitrogen narcosis, known as the ‘Rapture of the Deep’, can make this quite interesting and challenging. Descending past 100 feet, a diver may feel like they are in a ‘euphoric state’ or have symptoms of intoxication. Decision making and skills can be dulled. By the time all three have completed this, their time is up.