Leg cramps in the pool??

Hey Everyone,

Suddenly I've had 2 back to back nights of pretty decent calf cramps while doing an intense pool class called Navy Seals. I thought maybe I had bad form last night or wasn't hydrated enough but I paid close attention to all of that today. Still I found my calfs twitching like they would seize up every 10 minutes or so.

Thoughts??!! I love this class and don't want to give it up!