Mine has been down well past 100 on multiple occasions and down to 130’ once with no issues. You do need filters and a good strobe would help with the lighting. One thing to note, the GoPro has a VERY wide angle on it. Whenever I try to take, what I think is a close up shot, it’s still pretty far way. I have gotten to the point where I use the GoPro for video and I use another cheap setup for my stills. I wear the GoPro on my head and carry the still camera. I have seen rigs where people mount their GoPro and their Still (Sealife or whatever) on the same bar with strobes. Now you have your still camera and your video on the dive, but only one thing to carry and operate. Good luck with it. I think you’re going like the simplicity and the video quality of the GoPro. I love mine!!