I have joined Videoblocks and downloaded some of their stock clips. Here are two of them alongside the one I originally downloaded from YouTube which I would need to edit.
This is the original downloaded from YouTube. The sound would need to be replaced because the music is inappropriate for my exhibit. It is much longer than most stock film clips (2m 31sec). I could not make something similar myself with the Vuze camera as the waterproof case is as yet unavailable until 4Q. I am disinclined to buy another for this.
The speedboat is either a benefit or a problem. If used the boat would need to represent the optician and his crew dashing to the scene. There is no sound. It is also very short (15 secs) so I would need to see that there was no glitching when it is run continuously.
This is similar to the above, but less frenetic and without a boat. It also has no sound. It is also very short (11 secs).
So I need to look at stock sound clips too. Here is one source.
I have searched for Spatial sound of Seagulls but cannot find any. I will need to check how to do this and possibly this is something I could consider doing myself. I will see.