Scuba diving. A subject near and dear to my heart. I was a Dive Master for several years. I also have my Rescue Diving certification. I've let my Dive Master Certification lapse, however, and haven't been in the water in several years, but it still calls to me. A lot!

Scuba diving for recreation is amazing exercise. Scuba diving is putting yourself in an environment that inspires awe and a high level of respect for elements that are totally out of your control.

I dove mainly in the Pacific Northwest, in Puget Sound and frequently in the San Juan Islands. The water temperature, currently 52, fluctuates about 5 degrees year around, is slightly murky in warm weather, with plankton blooms, clearer in the winter. Nothing like diving in the tropical regions. The currents are fast, and unpredictable. In the San Juan Islands, there are areas where multiple currents collide and you HAVE to understand these, and be more than prepared physically and mentally.

I was lucky enough to work with some of the best instructors in the area, as their dive master for classes. There were some scary moments when students thought they could handle elements they weren't experienced enough to handle. I had to chase more than one student who got caught in currents off of rock walls. It's a fascinating world, but recreation diving isn't commercial diving.

Commercial diving is a whole different animal. It's a physically, mentally, emotionally challenging occupation. Some of the education can be acquired through schooling at a Commercial Diving school, some can be obtained through an on-the-job training program many companies offer. To obtain an OJT program, most companies require extensive prior experience and education. They aren't going to take a weekend diver and put a cutting torch in their hands and drop them to -200 feet to repair an oil line, or the hull of a ship in high seas. There are some jobs that are so specialized there are only a handful of individuals world-wide capable and available to perform.

Commercial diving schools will teach you the physics and physiology of the underwater environment, how it effects the human body (compression, nitrous oxide absorption, etc.)

Commercial divers have a extremely demanding career, requiring a high degree of psychological and physical fitness. You have to keep yourself in top condition. You need to pass a long list of medical examinations to be approved by the Medical Examiner of Divers (AMED) before you can even begin to start training.

These conditions will be checked in the examination. If you fail to pass, you won't be accepted in the diving programs, or restricted in the types of training you'll be allowed into:

• Heart and Circulation: High/low blood pressure. Condition of your heart, including angina, chest pains, irregular heart beats.
• Condition of your lungs, including oxygen uptake. Asthma, smoking, history of pneumonia
  
• Stomach or intestinal conditions.
  
• Upper respiratory conditions: Ear, nose, throat, sinus conditions. Diving puts A LOT of pressure on your sinuses.
  
• Psychological stability: Mental health - Claustrophobia is a major one you'll deal with in diving. Water pressure at depth gives you a serious "closed-in" feeling.
  
• Neurological examinations: Checking for conditions like epilepsy, motion sickness, inner ear imbalances. Blackouts or fainting spells.
  
• Conditions or diseases of the head: Headaches, migraines, strokes, multiple sclerosis.
• Injuries to the body, including but not limited to: Head, neck, spine, joints, arthritis.
  
• Diabetes
• Pregnancy – A diver who is pregnant or who suspects she may be pregnant should not dive.

"To say there are hazards seems unnecessary, but I'll say it anyway. There are hazards!!! You are breathing oxygen/mixed air underwater, in currents, at great depths. I've been down to 120 feet. The gravitational pressure on the human body at the surface is 14.7 pounds per square inch (ambient pressure). At 33 feet ambient pressure doubles. At 120 feet it's more than four times.

So let's talk about the "bends." A nice little term for a very nasty, and potentially deadly condition.

Decompression illness ('the bends") is a term that describes what happens when nitrogen that has built up in the tissues of the body (pressure builds them up and holds them in) are released into the circulatory system. There are many variables involved in the amounts of nitrogen that the body can hold "in solution". Body mass-fat/muscle is a big one. A decrease in pressure will release these molecules at a high rate, the body cannot eliminate them through respiration fast enough and so they rise to the highest points of the body.

Can you say 'joints', 'eyes', 'BRAIN'??

Another is bone necrosis or in fancy pants terms; "Dysbaric Osteonecrosis". Don't you feel smarter just saying it? Astronauts have similar issues with bone degeneration due to extended periods in a gravity-free atmosphere. It's a degeneration of bone tissue similar to osteoporosis, but more aggressive.

So you made it through the last section and you still want to be a commercial diver. I say "Bravo!" If you get in, you'll be a member of a select 'fraternity' of men and women who I have a lot of respect for. So what can you do as a commercial diver? The field is wide open, but if you're living in an area that has no water, no dams, you'll probably have to look forward to moving.

Here are a few of the many jobs for Commercial Divers. 

Diver Medic Specialist programs.

Underwater Welding: air and mixed gas specialists.

Underwater Riggers:

Underwater Burning Specialist.

Diving instructors (NAUI and PADI certifications)

Topside Welding Specialists.

Underwater Construction

Hyperbaric Chambers.

Underwater Inspections.

Inland or Inshore Diving (as support to civil engineering).

Salvage Diving.

Wreck Diving.

Treasure Hunting.

Rescue Diving.

Police or Armed Services Diving.

Tourism Industry.

Time to learn your 'laws', Charle's Law, Boyle's Law, Henry's Law.. "Volume, pressure, and density"

Then remember Murphy's Law!

Get out there! Go for it!!