I'm getting a Fantasea FRX100 IV Housing to use with my Sony RX100 IV. Long term I want to use it in the ocean while scuba/snorkeling, short term, I will use it in my pool while learning to use it. I have only used a GoPro as a point-and-shoot underwater, so I know nothing about underwater photography technique.
I plan to shoot in Manual or Shutter Priority Mode to capture the action of my kids playing, about 1/250. The kids will be no more than 3-4 feet under. Based on this, do all the same principles of photography apply when shooting underwater to get a good exposure? Which metering mode is better underwater?
Thanks for any help!

