The Canon G7X III is a tiny camera with a large 1-inch, 20 MP sensor, a direct competitor to the Sony RX100 series cameras. It is an excellent, fast-focusing camera with great image quality and has dedicated macro focus. The camera also boasts 4K video, slow motion video, a bigger image buffer, a new stacked sensor, a better image processor, and quicker burst shooting over the G7X II.
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.