It starts at the Sailaway Party, they will probably teach you the Cha Cha Slide, which is a blast. They also do the other usual line dances, like the Electric Slide, in the adult night club areas at times and I'm pretty sure they do them in Studio Sea (for the family) too.
On the 7 day I know they have a line dancing class at some point during the week during the day. I believe one or two members of the cruise staff teach it.
GET UP TO A $1000 SHIPBOARD CREDIT AND AN EXCLUSIVE GIFT!
If you make your Disney Cruise Line reservation with Dreams Unlimited Travel you’ll receive these incredible shipboard credits to spend on your cruise!