1

Trying to find a good underwater camera to use to film my competitive swimmers and review on a delayed video feed like 15 or so seconds laters.
Anyone got any ideas on what kind of camera would be best, trying to get 1080p 30-60fps

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The problem with using underwater cameras is that you can't use Wifi (when underwater) and USB connections are difficult to waterproof. But something like https://www.aliexpress.com/item/32967094275.html may be OK if the swimmer is within a few meters of the camera.
The other option would be to use "any" suitable land camera and make a suitable waterproof box from acrylic sheet