Great job with your edit between raft and kayak! And great runs.
The rear-mounted, high camera is a great perspective. I'm also not a fan of helmet-mounted shots. I think they can work well as complements to the stern-mounted camera. But not as the principal shot.
(Agreed! they are way over used and are a great way to show some action and added details)
One thing I learned, though, is to put the camera to one slide, slightly offset. You can see the bow a bit better. (In my video showcase, see the video on Slab Creek.) I paddle-guide on the left, so I've added a d-ring and bent a cheap paddle with a mount that puts it up and right at the back "corner" of the boat.
(That is an interesting idea i have not thought about, I like the angle you capture with it. I will have to give that a try.)
I learned not to use "Superwide" after doing a video on the North Fork American. It's too fisheye-looking. "Wide" (as I think you used) or "Linear" is best.
(I have played with this as well but have found I like the superwide view for the stern mount, on my last Grand trip I inadvertently switch cameras with out realizing it and the stern camera was set up of a narrow FOV and it did not capture the scale and view that I wanted. You do trade some depth of field but I like to see the scale of the river and canyon. Another note, that with GoPro camera there is not real zoom so they just crop the image for a narrow FOV so if you shoot in wide you can always crop it down later and get the same effect)
I wonder what your settings are? I'm using 2.7k, 60 FPS so that I can use slow motion in post.
( I normally shot in 1080p and 60 to 120 fps depending on the camera. I don't really change this much, I would like to play a bit more with slower frame rates around 24fps and work on the cinematographic look.)
I've also created a mount using PVC that works through the front d-ring and the handle using one strap. I've broken the thing about five times - and lost a GoPro 5 when it was decapitated by another dude's oar who'd gotten himself stuck on a rock in front of me. But I've learned to tether the thing using a cable, and it's improved over time. I'll try and find a picture of the mount, which is cheap and easy to make, but has taken some iterative engineering to get right.
(My front mount is also PVC but not as high as yours. I like the point of view you get but that seams like i would be prone to damage as it sound like has happens. My mount in tight to the tube so only stick up a bit more that the height of the camera and have not had any issues. Some time I will also just use one of the GoPro adhesive mounts and stick it to the boat. This only woks on rubber boats. I tried it on my SOTAR and it did not stick well enough.)
But the slightly elevated, rearward-facing view is really fun for the paddlers.
Another note: The GoPro 7 (and now
has this amazing image stabilization that makes it look like the camera's on a gimbal. It's crazy cool. You'd think it would make shots more boring; it doesn't.
Also, the GoPro remote is a little flaky, but once you get the hang of it, indispensable in turning multiple cameras on and off.
(I got a new 7 for this trip and do like it be have not figure all the bells and whistles out yet. I use the remote with my old ones and when it works it is awesome, can you still use the old remote with the new 7/)
Here's a library of my footage from the last couple of years. In the "Flip on the North Stan" video, I broke both lens covers on two GoPro 7's. (And my daughter's nose.) Fortunately, the lens covers are easily replaceable at $20. (The GoPro 8 does not have this feature; replaceable lens covers, which is disappointing.) (My daughter, a gutsy girl, has forgiven me, and still loves the game.)