If you want airborne images, the normal answer is to buy a drone. On the other hand, you could just load a GoPro camera into a water balloon slingshot and fire it over the water. You'll need a stabilizing tail as seen here to keep it pointing somewhat straight.

Step 1: Tail Assembly

The assembly was made out of a piece of packging foam. Split the end that will be opposite the GoPro and compress with a zip-tie to flare it out. Use a 1/4-20 eye bolt on the other end. Feed through and zip-tie as shown. A bolt on the end will allow it to connect to a GoPro tripod mount.

Tail should be made out of buoyant material to keep the GoPro from sinking.

Step 2: Load, Fire, and Retrieve

Securely attach the GoPro to the tail assembly, then load into the water balloon slingshot and fire! Use a floatie backdoor to keep the GoPro buoyant even if it separates from the tail.

As seen in this image and the video, it helps to have a canine helper to retrieve it for you!