they are WAY slower than usms nationals.
and nobody in fina cares if you cannot make it either.
in 2012 italy there were 60 guys (thats 6 heats of a 10 lane pool) of my age group alone that did not make the entry time!
took me under 30secs to find
www.fina.org/.../budapest2017_masters_qualtime.pdf
People may not "care" that you make the qualifying times but your times will not be posted after you race if you do not meet them. So while the Qt are lenient there is an incentive for everyone to try to make them. I missed it once in California. Not a great feeling to see NT after your name.
