I have this Airhead G-Force for my kids.
It's a flat one with no hole in the middle, I felt this would be better for little kids, I got it two seasons ago when my girls were 5 and 3. It's also good for lounging when the boat is parked, it's kinda like a mini-island, the kids love to climb up on it, see how long they can balance standing, and then jump off. It blows up pretty quickly, and I can tie it up to the ski eye on the back of my 89 Supra Sunsport and it just rides on the swim platform with just the back end barely dragging the water. We've even wakeboarded with it tied like this, no affect to the wake, and no damage to the tube so far. I found this tube to be a great size and manageable to tote it around all day. We can also tie it down on top of the open bow and it doesn't catch wind and driver can still see over it. With one of those big loungers you'd have to take it down and let all the air out if someone decided to wakeboard. This one also stores in the back locker of my DD Supra along with all my (empty) ballast bags (450, 2x 750s, and 350). Make sure you consider how you would store or haul a big inflatable around on the boat, both deflated and inflated.
The only negative to this tube is it is prone to the submarining issue some have discussed. If your kids are old enough big enough to know to lay on the back when getting started it's not a problem. My solution with my now 5 and 7 year olds is to tie the rope off to the tower, start them at idle about 15ft behind the boat, with someone standing on the back locker letting the rope out slow. The higher tow point with the tube close lets you keep the nose up until the water runs out of the back vents. Once the tube planes out we let the rope out and continue increasing speed to about 15 mph. This method won't work when they get much bigger, but by then they should be big enough to put their weight off the back when getting started. Kind of a pain in the butt... but I didn't want to buy another tube no more than we use it and I've found there to be so many other positives to this tube. They usually want mom or dad riding with them anyway so the submarining is not a problem with an adult on the back.
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