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. You will also utilize underwater video with helmet mounted cameras as used in commercial work. You’ll rotate through all dive station positions, including dive supervisor.|
|Week 3||Diving to 160 feet. Here you will need to perform 2-6 minute decompression stops (50 feet for 2 minutes, 40 feet for 6 minutes) in the water column. Next you are up and over, straight into the chamber.|
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.
Watch: Surface Decompression
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.
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.
An ROV is an aquatic robot attached to the surface by fiber optic cables that allow for remote piloting, data collection and sampling. First developed for industrial purposes, ROV’s are now used for many applications and have proven extremely versatile in ocean exploration and assisting in dive operations. Before a diver enters the water a ROV can be deployed to identify problems, search for damage, or help determine the course of action to resolve issues ultimately saving the diver valuable underwater time.
On board the MV response we have a VideoRay Scout Economy ROV system (PAL). Our Scout is a submersible, remotely operated vehicle, (ROV) designed to take advantage of its portability and size.
- Depth Rating of 250’
- Maximum speed of 1.9 KNOTS
- 14inchs long / 9inchs wide / 9inchs high
- Weight 8lbs
Students at DIT are introduced to the benefits and limitations of an ROV during their deep dive module. While dives up to 165ft are being conducted, simultaneous ROV operations are taking place exposing students to piloting, tending, data collection, and equipment maintenance. Our crew continues education on inspection of vessels, (ie: anode, hull damage, rudder housing, and props), monitoring the divers while working, and general inspection.
With the increasing use of ROV’s in our industry it is imperative that students learn to incorporate the abilities of the ROV into their dive plans.