Underwater place the crown of your head against the middle of the + mark.
While staying underwater, and keeping head pressed to the wall, do 3 Breaststroke Kicks
Float on back in SL. Press legs and feet together too. Only wiggling body like a worm switch orientation. Rotate so feet go where your head was; remaining on your back the whole time.
Push off the wall with your hands at your side in soldier. Press the inside of your feet against the wall and push. Like breaststroke kick.
do it again on your back.
Get past the flags.