Dogs, Fishing poles, long sticks, onboard battery-driven propellors, radio-controlled boats, and tractor beams are all useful. Sometimes.

Ultimately, you're going to need a boat. You will have to get in the water and physically retrieve your airplane.

The other things are handy for those times when you can get by without taking a boat ride. A man-carrying boat will ALWAYS get the plane. Any of the other tricks works SOMETIMES. Which is fine if you USUALLY want to get your plane back.