I have used Go Pro's and the much cheaper copies.
Tried controlling them from the phone App, but that takes time and eats the battery.
The cheaper ones have a control that you cam wear on your wrist that is useful, there batteries also last much longer.
The fact that they are in a protection water proof cover helps, but because of this, sound is an issue
The recent Falmouth trip I had some great video of Jerry's fight with the biggest beastie, but the sound was as I say poor.
My biggest problem is the time taken to edit.
Images and videos taken on the phone do not have the same problems but I am not putting my smart phone in the salt water