I was checking the Port Everglades webcam to see which cruise ships were in port today just as a US Navy submarine was leaving the port. According to the audio chatter, the port was closed while she was leaving port. I grabbed a couple of screen captures of her which you can see below. She looks like a Virginia class attack submarine. The shape of her sail and the markings on it match photos I found online of Virginia class subs.
Port Fever posted a couple videos of the sub on YouTube. The first shows several people leaving the sub followed by their gear. The second video is of the sub leaving port.