If you're looking for a solid secondary camera for underwater shooting with good low-light capabilities at 1080P, the Olympus Stylus Tough TG-5 is definitely a great option to consider. I’ve used it myself, and it holds up well in challenging environments, especially where you wouldn’t want to risk more expensive gear like your A6300. While it’s not perfect in extreme low-light, pairing it with underwater fishing lights or any strong external lighting really helps improve visibility and color accuracy. These lights make a huge difference when filming deeper or murkier waters where natural light fades. Plus, the TG-5’s rugged build means you don’t need to stress about housings or minor impacts. If you’re hesitant about GoPro quality in low-light, I think you’ll find the TG-5 a more reliable alternative, especially when combined with the right lighting setup.