This article, Water Flicker Technique, is property of Waterkai.
Ikaiyo's signature technique, it allows the rapid movement through water molecules. the amount of water doesn't matter, thus resulting in the technique being able to used virtually everywhere. Ikaiyo has mastered the technique to the point that many people believe that he used Space/Time Ninjutsu to teleport himself to another place, while he actually moves through the water molecules in the air. This allows him to dodge even point-blank attacks, and makes it incredibly hard to hit him in battle. It is unknown if a hand seal is required every time the technique is used, but Ikaiyo claims not.
This technique can also be used to move through solid objects and even living creatures, making only chakra barriers effective against Ikaiyo. The speed at which he performs this jutsu is amazing, only shimmering for a second and looking as if he simply dissipated, even to trained eyes. Meifuku states that even her Sharingan can't always keep up with it, implying the effectiveness of this technique.