Who holds the record for the fastest 400 meter swim?

Answer(s)PREVIOUS ANSWER #1: the most i have ever seen is someone who did three lengths of a 25 yard pool.

PREVIOUS ANSWER #2 ...I regularly swam 2 laps underwater in an Olympic size pool (total 108 yards) -

MY ANSWER:

My total distance on one breath underwater is 110 Meters or 360.89' that's 2.25 lengths of the Olympic pool.

I can also hold my breath exhaled (no air in my lungs) and sit on the bottom of the pool for about 60 seconds. One time I got the life guard off of his stand and almost had him in the water and everyone else was making quite a fuss when I came to the surface unharmed. :)