String Theory – Light Streaks Creative Titles
https://elements.envato.com/string-theory-VH86MCK
Free 
Realistic Water Wave Transitions | 4K
https://elements.envato.com/realistic-water-wave-transitions-4k-6GFXC6N
Free 
Cinematic Drama Trailer – Underwater World by vparallax on CGguy
https://elements.envato.com/cinematic-drama-trailer-underwater-world-5SEFN7W
Free