Has Crocodile already "awakened" his Devil Fruit Power? Crocodile is the first villain that easily beats Luffy (twice) while Luffy survived due to Robin's interference and luck. However, one of the comments on his devil fruit power struck me. 

Chapter 178: Wikia (Anime Episode 110) Emphasis mine


  Luffy is astonished at Crocodile's power while Crocodile comments that he does not just possess his devil fruit ability like some people, he mastered it and demonstrates this by creating a hole of quicksand.


Crocodile can absorb moisture and convert anything to sand, i.e. he can permanently convert something to sand. He also completely annihilated the palace garden. He can create large sandstorms which can run for days. He can control sand in the city which can cover it like a fog. These abilities seem to point in a direction outside the limit of Logia powers. 

We also know Crocodile knows about awakening. In Chapter 544 Crocodile is the person who tells us about the awakened Zoan type Jailors 


  Crocodile then reveals that the Jailer Beasts were all "awakened" Zoan Devil Fruit users, saying that their extreme physical endurance and recovery point were their advantages. Crocodile states that the other three would soon awake and that the Boss of Hell would be arriving soon. 


So is there some reference about Crocodile and his DF powers? Maybe something Oda has said in SBS, about crocodile, limits of Logia powers or Awakened Devil Fruits.

Other Observation: Akainu and Aokiji may have awakened DF's since they converted Punk Hazard into Freezing side and Burning side permanently. (Also Akainu burning Ace). Enel may have a hand in the island that is permanently spewing lightning etc.
From how I see it and how it's described in the series, the awakening is the ability to manipulate the environment e.g. Doflamingo's awakening. Like when Kuzan and Sakasuki went at it on punk hazard and permanently changed the weather.

Another example is when Crocodile turned everything around him into the sand during his second fight with Luffy (Mizu Luffy)(Chp 201). Also, there are the times Crocodile talks about "utilizing your devil fruit better"(Chp 178) or being "a different breed of pirate"(Chp 178) though this may just be Crocodile being cocky. He seems to have a vast knowledge of devil fruit awakenings anyway as he was the one who informed us about the jailer beasts being awakened and even told us the effects had on them.(Chp 544)

Also, once he was defeated, it started to rain again(Chp 210), and though many people say "Oh, Smoker used the dance powder on Crocodiles ship" or "Crocodile used the dance powder another place to keep it from raining", but Smoker specifically said to Hina that he didn't (Chp 212) and that would have to be perfect timing so I think Crocodile is awakened and can keep his devil fruits weakness away.