User blog comment:Airagog/Calculating the power of each magical spell/@comment-6529023-20140513214909/@comment-5974425-20140515114740

I always figured that advanced water magic was basically freezing the core of a water surge into a cone. It takes a huge amount of force to make a drill-like cone of water cut through metal, so I figure that freezing at least part of it would be a good go-between for water magic cutting metal. Ice magic is water magic in RS, only the Ancient spellbook has a mastery of it that the standard one doesn't have.