Cheapo Raft
I just use an inflatable raft from Academy or WallyWorld. The size made for 2 people is perfect for a 12v car/boat battery and a cooler. Just make sure your tether for the raft is shorter than the battery cord for the light, or everytime the raft floats back the light will come unclipped. It works best if you put the battery in the front, and then the cooler behind it. I had to lengthen the battery cord on my light, but it was worth it. Also, since it is supposed to be a boat, it supports lots of weight and tracks well as you tow it behind you too. Little kids or overserved fishing buddies can also ride in it if need be!