Like I mentioned, underwater housings can cost more than the camera itself so choosing the right one is an extremely important decision. They do more than just keeping your camera dry. They also protect it from pressure, allow you to use the camera controls, enable the use of different lens ports and hold accessories like lighting. Be sure to invest wisely on this one!
Another highly sought-after, and relatively exclusive, feature within the video camera realm is the ability to record in RAW or ProRes. These are uncompressed formats that maximize the information gathered by the sensor and provide you with extended flexibility when it comes to color grading and post-processing. As mentioned, this feature is quite an exclusive one and only available in a select few cameras on the market with good processors (again, excluding high-end cinema systems). Some select cameras can record in ProRes Raw with an Atomos Ninja V external recorder. Nauticam offers a housing for the Ninja V for use with your underwater system.