Sorry, there doesn't seem to be a Tube or Pontoon site and I don't own a Kayak or Canoe, so forgive me if this is in the wrong spot.
I just purchased the Freestyle H3 wich is a Super Fat Cat on Steroids.
This is the BEST IMO tube on the market. Six feet long, and very stabile.
I am sitting at least 4" off the water with the inflateable seat and the old man at 6'3" and 225lb was not much lower, but the wind resistance was minor.
Great cordura outter cover and Urethane bladders.
Got to test drive it this last Sat. and it is SWEETT!