In 2016 I was sent to Costa Rica in order to attempt to capture an element of the opening sequence for the 'COASTS' episode of Blue Planet 2.
What I had been sent to film, was a turtle arriabada - an event where many hundreds, even thousands of sea turtles haul out and nest simultaneously. 'Arribada' is a wonderful word, borrowed from Spanish, literally meaning 'landing' or 'arrival'.
I was to film the underwater segment of the sequence, where the turtles rest on the seabed in the bay after their long swim from many different corners of the ocean, to this one beach where they all haul out. This was supposed to be a very simple task, but the turtles proved to be A) harder to find than we'd been lead to believe and B) once we'd found them, far harder to approach underwater than we'd been lead to believe!
This lead to many many hours of swimming underwater on rebreather, doing search patterns to find the turtles which were widely spread out. What with the underwater visibility being very poor in the area, just finding them was a real challenge. One we found the turtles, I was generally only able to grab one or two shots of them before they spooked and disappeared into the gloom. I also spent many hours at the surface, attempting to approach turtles what had come on the surface to breathe. The intention being to film 'split-level' shots of the turtles, to show them gathering near the beach. After much frustration and many failed attempts at approaching turtles at the surface, I eventually found one turtle that was not bothered by my presence and allowed me to film for as long as I cared to.
In the end perseverance paid off, and we got the shot we needed to tell the story of the mass arrival of these turtles, which I think made for a great opening sequence for the COASTS programme of the series.