Walmart offers H2OGO! River Gator Swim Tube Pool Ring Float for $4.98 (orig. $10.98).  Free shipping with Walmart+ or on orders over $35.

Product Description:

The H2OGO!® River Gator Inflatable Swim Tube ring pool float is anything but scary. In fact, it will bring hours of fun to the pool, beach or lake! With a cool gator design and a wra paround grab rope with built in grommets so that kids can easily climb into the tube, splashing in the sun has never been better. This ring float provides ultimate floating experience.

• Age Range: 12+ years
• Easy to inflate, deflate and store
• Contents: 1 swim tube ring float, 1 repair patch