My 96 XP is 110 hp, your HX is 85 or so, if I am not mistaken.
My 200lb father pulled my fat 220lb butt up on waterskis behind mine, fairly easily, I should add. I popped up pretty quick, and would have been quicker if dad had nailed it a bit harder.
I don't see how yours should have a problem pulling a tube and passenger of moderate proportions.