The Splash Drone is a waterproof quadcopter that does more than just merely land on the water -- although that's pretty awesome in itself. It is also capable of capturing photos and video beneath the water surface. Developed by Urban Drones, the Splash Drone represents a far more affordable alternative to more expensive waterproof drones such as the HexH2o.
The Splash Drone can be used in conjunction with a GoPro camera that is mounted to its underside using a waterproof gimbal. The drone can then be flown out and landed on the water. The drone will then float on the water with the camera submerged underneath, before it is instructed to take off again.
This waterproof quadcopter is currently the subject of a Kickstarter campaign. A pledge of $799 will get you set up with one if and when they make the market -- this price represents significant savings on the planned retail price of $1,199.
This is a reasonable price for a quadcopter that looks like it will be fun and fulfilling to use.