Re: help-- looking for tips on pulling a tube for the first time
A couple points that haven't yet been made... If / when someone falls out of the tube or it flips, throttle down right away... the overturned tube sometimes will land upside down and catch a huge scoop of water that can make a big pull on the rope.... Get into good habits when driving with fallen riders in the water. I always approach / go around them with them on the driver's side of the boat. That way, my view of them is never blocked by the bow/hull. Don't ever drive close to them, and always be going slow enough that you're not making waves and can talk to them. If you're gonna switch riders, or they're quitting. Shut the motor off before they swim up to the boat.
If you have a swim platform on the back of your I/O, it is much easier for them to climb up onto that, and then jump into the tube than to climb in from the water. But again, engine should be shut off before they even start towards the boat.... don't forget to put the boarding ladder up and run the blower before you fire up again. (better to just leave the blower running). BTW, my kids are the same age and already know that you never swim up to a boat with the engine running. As I'm coming up to them, they'll say, "shut it off, I'm coming in". So, don't be afraid to explain to the kids why you do things certain ways. They learn good habits.
And ditto what's been said above. Make it fun for them, and don't make the ride scarier than they want it to be. We almost always pull 2 single rider tubes at once, on separate ropes. The only additional thing to be careful about then is to not whip the tubes so they bang together hard. This is a problem when one rider slides side to side easily, but the other one doesn't move as much. It would ruin everyone's day if the little ones banged heads. But a little rubbing and the ability for them to talk to each other while tubing seems to add lots of fun. We have hand signals for speed up, slow down and zig zag. The kids like to have some input about whether the ride is too easy or too scary. Usually one tuber is giving the zig zag sign, while the other is shaking their head "no". Part of the fun. As a driver, I listen more to the timid kid, than the wild one. If it's too tame for them, they can go by themselves (which they almost never want to do).
BTW, I've got a 17' searay with a 3.0 mercruiser... yes it is more than enough. My kids are usually going at 'just planing nicely speed' which is around 20 mph or just over. It is a very fuel efficient rig for pulling kids.
Have fun!