Here's my experience with unions.
My brother was the manager of the largest water park here in the Phoenix area for five years. This winter, he was offered big bucks to go back to the east coast and work for a Six Flags waterpark which had been underperforming.
When he arrived, he did, as he did every year with his former job, had everyone pass tests of first aid, swimming, lifeguard knowledge, etc.
To his surprise, four of his top employees, including the former supervisor which he supplanted in a newly created position, couldn't even pass the basic swim test. Two of those were the department "instructors" who taught other lifeguards the basic skills to get them certified.
So he moved to have them fired right away, as you can't have lifeguards who can't swim, especially one's in power in a major meto water park.
Turned out that when filling out the job requirements, someone neglected to mention "swimming" and other life saving aspects as part of the job, so the union was able to block the four employees firings.
His response was to move those four individuals to the lowest areas where their lack of skills could do the least amount of damage, but the Human Resources dept has told him he also can not hire four new employees to supplement those four.
The union was also able to stop it the first month when he reduced each full time employee to one shift, as they were hired for a minimum of X amount of hours and because they hadn't been fired.
So the end result, was he had to write all four up to put it on record, and is forced to have each work a minimum of 30 hours at their jobs, on the cusp of saving lives swimming in the water.
The morale of the story - I won't tell you which Six Flags it is, other than it's in the upper east coast region of the country.
But if you're taking a visit this summer to any of that company's water parks in that area, watch your kids at all times, because those type of lifeguards, those who can't swim, is your safety net for keeping them alive.