Here is another drone that can perform in marine environments. The IdeaFly Poseidon 480 is a waterproof quadcopter with a 3-axis gimbal and 40-minute flying time. It can land or takeoff from water. You can also use it as a fishing tool.
The drone has a max take-off weight off 3.8kg. It comes with a 16MP camera with Bluetooth. Its max vertical speed is 6 m/s.