A lot of stuff works ....sometimes.

A long pole with a generous-sized hook on the end is useful.

A tennis ball on a string, or A spincasting rod with a weighted bobber can snag the plane and drag it back sometimes, but having a pole in your hands inexplicably tends to make the wind blow from you toward the airplane so it is out of range in one or 2 casts. FOr more range, a bow and arrow with a fishing reel will project a retrieval line out a long way.

An R/C boat towing a bobber with a grapple on it is pretty simple to run. just circle the plane until it's snagged, and drag it back.

Check the math: You can BUY a jon-boat for the price of a r/c boat+batteries, radio, charger,ESC, etc. ( Or a compound bow with a fishing reel on it) With a jon-boat, you can retrieve your plane from the god-forsaken brier patch it drifted into, or you can pick up the floating fragments after a major malfunction. AND, you can use the jon-boat for other stuff.