Skating Drill - 45 or 90 degree rotation?

Hi!

I've been doing the TI drills for about a month now and today I've finally succeeded in doing the skating drill without swallowing gallons of water! I am, however, unsure whether I did it correctly as I have read contradictory information regarding the body position. My TI book says the following:

"Swivel your head and look directly at the bottom, rolling to your side as you do. After you look down, pause and check: Are you looking directly down? Are you balanced on your side with your shoulder pointing directly up? Is your extended hand below your head?"

To me, this sounds like a 90 degree roll. Some videos on Youtube show more of a 45 degree roll though: https://www.youtube.com/watch?v=neokpjNKMYE

Which one is correct?

Thanks in advance!