Float tubes or Belly boats are pretty safe. Lots of different ones available.
There is a float tube association where you can get all you need know.
I wouldn't mind some fishing as in the video, I think need to make a new friend /forum/smilies/smile_smiley.gif/forum/smilies/smile_smiley.gif/forum/smilies/smile_smiley.gif
I've fly fished in one a couple of times in Northern California. Found it very hard work to cast a fly as I was so low to the water but great fun. Had a couple of trout which span me round a few times!
Wendy has fond memories of such craft as well!!/forum/smilies/big_smile_smiley.gif