What hp outboard or i/o for tubing?

I am thinking about buying a 13′ to 20′ boat for fishing, cruising and tubing. I am of course buying a used. It will be quite old because my budget is limited to under $600. Anyway i have found a few but this is the one im thinking on. It is a 1960′s boat, outboard motor and trailer. It is 55hp. Will this be enough to tube at higher than slow/medium (not at break-neck speeds)????? If not what hp would be the minimum comfort zone for tubing??? We are most likely not going to ski or wakeboard with this boat.

I gotta agree w/carnes there a 55 horse boat will pull it, but as soon as you make a turn, the boat’s gonna slow way down, plus it won’t have the go off the holeshot so gettin’ up on plane is gonna be slow, you’re gonna need at least a 100 horse engine to pull a tube behind. we wakeboard and it takes a buck an a quarter engine just to give us a good pull.

so you may have to upgrade to a bigger engine to get a good pull behind the boat.