Swim- yishun safra

Was at the yishun safra pool last nite for my regular 30 lap swim, bump into tiwazz who was observing the national biathlon swim trial. After a few words with him, me and jon head in for the swim.

Jon a friend of mine does his breaststroke with his head above the water. Something i can't understand is how the hell can he swim faster then me in that fashion? ..just cant understand i thought you are suppose to be able to glide underwater with the head in the water and should be faster?

Anyway my 30 laps timing is as below
1st 10 laps : 14.30
2nd 10 laps : 15.00
last 10 laps : 14.00 approx