GoPro Hero 8

Is it worth the upgrade from the Hero 7? Any thoughts on the Hero 8?

I would say no for underwater shooting, different housing so if you have any filters or lenses with your 7 they won't fit. 

No improvement for underwater filming except the higher bit rate.

I do believe the image stabilization on the GoPro8 has been improved and so has the automatic white balance.  Is it enough to warrant buying a new camera - probably not.  And yes you will need a new housing but the price is pretty reasonable about $50.

Here is an example of the GoPro 8 that I shot here in San Diego California.

It is really nice, thanks for sharing. few years back - before the GoPro era, it would have costed a fortune to produce such quality steady footage. Now with negligible investment, one can produce quality imaging with an amazingly compact little rig

Thank you GoPro for making underwater imaging accessible the masses. 

This type of set for GoPro Hero 9/8 also can help to make perfect quality imaging