We were just in Nassau on Sunday and we were disappointed. We got off the ship fairly early and the streets were covered in trash and there was a lot of construction going on the route we walked to Junkanoo. The beach was so-so and there was some trash and locals that made us a little uncomfortable, we felt like we were being watched. I did not feel comfortable leaving my belongings unattended and there were no lifeguards. As far as the jellyfish... you never know where you'll see them it's best just to keep an eye out while you're in the water but we definitely saw more at Cococay if your cruise stops there. Jellyfish, fish, 2 stingrays, a small shark, and even a barracuda we saw. Looking back I wish I would have done an excursion to Blue Lagoon or Paradise Island while in Nassau. We ended up not staying at the beach long... we stopped in a few shops including the straw market and spent most of the day on our ship. PS. it seemed like a lot of more experienced cruisers didn't even go into Nassau when we got back on, they were all chilling by the pool and the casino!