Why does dry ice "dissolve" so quickly in water?

I just stumbled across an ancient video of some people putting a 60 pound block of dry ice in a swimming pool. Pretty cool stuff.

It's pretty interesting to me that in the video, the dry ice sublimates much quicker in the water than in the air.

I am wondering why this might be? Is it possible that water is acting as some sort of catalyst? If so, how can I picture this on a microscopic level? (That might not be possible to answer but the catalyst portion is.)

I was thinking that the $\ce{CO2}$ might be motivated to form carbonic acid, and by Le Chatelier's principle, the dry ice would sublimate even faster.

I'm not so sure that makes sense though...

I don't know. Any thoughts?

• Try it with water ice. With a bit of patience, you'll see the effect is still there - ice melts faster in water than in air. So, no - carbon dioxide is not the magic part, and neither is the solvent. What else is a difference between water and air? :) (hint: did you ever swim in cold weather? Which felt colder, water or the air?) Sep 17 '15 at 14:08
• Note that this doesn't happen with small amounts of dry ice -- there's so little convective motion that the water next to the ice freezes and insulates it. It's like a solid phase Leidenfrost effect but I'm not aware of any particular name associated with the process. Sep 17 '15 at 14:09

It's just about heat capacity + heat conductance, nothing more. $\ce{CO2}$ sublimates much quicker in the water because water is much better at heat exchange than air. Anybody who ever experienced swimming in water at 15°C and walking in air at 15°C can attest to that.
As to formation of carbonic acid, it hardly has any influence on the process (though it does happen to a certain extent, of course). Most $\ce{CO2}$ escapes in gaseous form anyway.