Re: Enough power to pull a tube?
I learned to ski behind a 14' with a 35hp. It takes a little work on the skiers part, but can be done. Though, a good tug from the skier can yank the stern around. Used to get into tug-of-wars with my dad driving for fun
It'll pull a tube, but probably the heavier the rider the more difficult time you'll have with it. It's not the optimum rig for tubing, but if you're wanting to pull the kids for a little bit it'll do it. If you're looking for those "give 'em a headache and put their stomach in their ankles" types of turns that'll send your 16 YO skipping across the water ... prob'ly not.
We've even pulled the little kids behind a 9.9hp - it worked for a starter.