1. remote control helicopter (from any toy shop)
2. remote control car
3. a light weight plastic scale
4. two empty plastic bottles
5. some super glue
Now first of all unscrew the remote control car and remove the top of the car. Now remove all the extra parts to make the car light weight even remove the batteries as now connect the car to the terminals of the battery of the helicopter and attach the lower base of the care under the helicopter with the help of super glue.
Take a scale and place it under the bottom of the helicopter, now attach the two empty bottles to the end of the scale so as to make it float over the water. You can either use one remote for both by adjusting the frequency of helicopter by changing the potentiometer present on the chip of remoter or otherwise just glue both the remotes to the best fit.
Now you are ready to go just fly your helicopter and move here and there and when there comes a place when you can’t fly to move ahead just land it conveniently and run on the path have turns and when water passage comes ahead either fly away or you can just float on water forward or backward just be sure to have monster truck type wheels on your RC car as it will help in water for the copter to move in forward or backward direction and for turning to left or right the back rotating wing can do the same work.
A spy wireless camera can also be installed in front of it to capture or record in various areas where one cannot reach.