I don't even think you need a condom for the LED water light. I tried to float mine several different ways and it didn't work. What surprised me is it went under water and still worked. I thought it would short out. What I bought is a cheap yard light you stick in the ground. So I just stuck it in a foot of water. Problem solved. You can take the extension off the light, and so the light might fit in a wide mouth canning jar. With a weight in the jar to keep it upright, you would have a floating light.
What clerk would believe you are buying a condom for a science project. And the condom would cost more then the LED light.
