User blog comment:Blackendedsoul/Unique Gomu Gomu/@comment-4684192-20120302213247/@comment-3425840-20120302213802

Eh well according to Pandawarrior and now also me, there are two other cases like Luffy's. As for the D thingy, I don't think that is the case as Robin who is not a D was also able to use her powers under water (she pushed the Sunny to cushion the attack of made by Surume).