Wow, exquisite work! Both on the location and in the post. I can see the benefits of stabilisation and I would only wish my GH5S would have one. Fingers crossed for GH6 :-). I was on a live aboard at about the same time in Red Sea. I've tried HDR delivery but had to mix GoPro footage in this as it's a field trip report, not a reel. Did you shoot v-log or standard and how did you deal with white balancing?
https://youtu.be/94lVqZEafbM