The answer is an underwater pole cam. For example, Aquatica and Gates have proper solutions for this:
- Aquatica Polecam
- Amphibico POV Flexcam
- Gates HMR10 / HCK10 (Point of View)
If your budget is none-existent, try a Gopro attached to a monopod which in turn is tied tightly to a sufficiently long DIY pole of any stiff material, e.g. a pipe. However, with a GoPro you will not be able to monitor in real-time.
With the GoPro App and the correct GoPro, you WILL be able to monitor real time. Even remotely control your GoPro.