Well, it needs oxygen like a human scuba diver but it lasts a pretty long time underwater just like a human would if he used an oxygen tank.
Recreational scuba divers only need to undertake a short course to be qualified (or "certified" using industry jargon). The certification process for a basic open water diver normally takes about 5-6 days.Commercial divers usually undertake some kind of vocational training, but this is not usually done through a college or university.
I am a Scuba certified and I weigh 150 Lbs, in my class there were some other people in the 250+ range, and there were people as light as 90 Lbs. Basically what I am getting at is that as long as you can swim you can Scuba dive. Average weight is very hard to determine since there are so many various divers.
They are potentially suffering the bends
Most scuba diving courses can be completed in about 5 days or so. PADI's Open Water Diver course has an online portion or in-class work which takes a couple evenings, and two days of actually diving - SSI and NAUI have similar programs, but resorts tend to take a little longer than independent shops.
It depends on how deep the diver goes, and what air blend the diver is breathing. There are dive tables that state how long a diver can stay at a certain depth before requiring decompression. The basic recreational diver typically breathes either air or Nitrox. There are separate dives tables for air and Nitrox.
Not necessarily. It just depends on what someone means. Scuba diving is only when you use a scuba tank or cylinder that a diver carries. Deep commercial divers will often get their breathing gas supplied to them through a long umbilical hose ... so they are attached and do not carry Self Contained equipment that they can swim with like a SCUBA (self contained underwater breathing apparatus) diver.
it takes 7 years to become a certified nurse midwife
Yes, the word "diver" is a long "i" word because the sound of the letter "i" in "diver" is pronounced as a long "i" (/aɪ/), like in the word "dive."
As long as he wants if he has enough gas to do the required decompression. But if you are asking what the no-stop time limit is, it doesn't exists since any dive to 100 meters (328 feet) requires mandatory decompression.
it takes 7 years to become a certified nurse midwife
Certified Medical Assistant takes 2 years.