Don't "test" your fire extinguisher... just look at the gauge or press in the check valve (small button on the top or side of the valve).
If the valve pops back out you are fine.
As soon as you use the extinguisher, even for a minute, the powder that is in there will keep the valve from closing and you'll need to get a new one.
I need to make sure the fire extinguisher works
I hope I can pull someone in a tube with 4 people in the boat and 1 on the tube.
We'll find out this Sunday, we'll probably weigh in around 750lbs.
I might pull one person in a tube with a life jacket on to avoid potential problems.
Oddly enough here in Michigan you can blow a .010 on a boat, but .080 in a car.
And BUI's are less troublesome than DUI's (While both are not good) in Michigan.