Round floating things in the big lake at Universal Studios Florida

[wingnut143]

Strange question I know, but we recently visited Universal Studios in Florida and my other half was fixated on what the 4 large dome things are that float in the large lake in the middle of the park. Does anyone know? He spent all day, every time we walked past them, trying to work out what they might be! I've copied and pasted a link below, the lake is at the top of the picture and you can zoom in a bit to get a better look. Thanks!

http://maps.google.co.uk/maps?hl=en&rlz=1R2ADB F_en-GBGB328&q=universal%20studios%20florida%2 0map&um=1&ie=UTF-8&sa=N&tab=wl

[spudqueen]

When I was there a couple of years ago there was an evening light show which featured these domes.