Well okay, technically it's not the water that's bioluminescent, but the bacteria (bioluminescent dinoflagellates) in it. The effect is the same: Find a bio-bay, go there at night, jump in, move around. Wohba! The water glows all around you - everywhere you stir it up.
There are a few of these bays around the world. The one in Jamaica and the one in Puerto Rico both have high levels of the bacteria creating a stunning effect.
Here are some kayaking photos.
Here are some swimming and pouring photos.
Here are a few movies of the bacteria in action.
Here are instructions on growing your own dinoflagellates.