This thread just saved me about $50. There's absolutely no question the Aqua Training Bag is just a repurposed Taylor Made Tuff End buoy. The available sizes are the same for both products. The nozzle is the same. Even the markings and branding around the hoop section atop the bag are the same. Everything is the same.
So I got a 15-inch Tuff End Buoy from JMS Online Marine Supply (
www.jmsonline.net) for $48, including shipping. I spent about $20 on a shackle, swivel and two carabiniers, and force-fed water from my hose into the hole without a water balloon nozzle. Pretty tough to find one of those in a dollar store in the Northeast on the edge of winter. No problem filling the bag other than my arms and feet getting a little wet.
JMS had the best price, and its service was incredibly fast. I got my buoy/bag in two days.
Aqua sells the same sized bag for $99, and it includes a swivel and chains. With shipping, the cost probably would be around $110-120. So I saved a cool $50. Stoked! Thanks again for the detective work that determined the Aqua Bag is a Taylor Made Tuff End buoy.