We have owned this fun tube for 3 seasons now. For 1-4 riders, Big Bertha by Sportsstuff is a great tube for water sport activities. It's durable, easy to tow, and safe.
This is one boat toy that we have had no regrets on buying. Compared to others that we looked at, Big Bertha is one tough tube. We have ridden and abused it for three years. The vinyl can take a beating from the water and the sun. There is an outer shell covering made of nylon parachute like material and it's tough too.
The product paperwork says that you can put 4 on it. We've only ridden two. The size does seem to accommodate that number though. It's 68" in diameter.
I'm not a dare devil but my husband is. He's been able to make the tube take air and jump wakes like a pro--he fell off once during his antics. I'm happy to just ride the wakes. Our teen likes to lay spread eagle over the top and see if she can get flipped into the water--that has not happened because the tube is so well balanced.
We like this tube so much that we take it with us on every boating adventure. I think it is perfect for family water sports and safe for kids. It is definitely well worth the investment.