The team from Te Mana o te Moana, who have been monitoring turtle nesting on Tetiaroa for over a decade, are walking kilometers of beach every night to record nesting and hatching events.
Usually contact between male and females occurs in the open ocean with the female then swimming over the reef to the motu to lay her eggs. This video though is of an encounter in the lagoon.
Since turtles do not practice parental care (eggs are laid and the baby turtles emerge from the nest and face the world on their own) it is very important that a female chooses powerful mates that will pass on their genetic traits to her offspring. One way for her to do this is challenge and fight males that approach her, driving off weaker individuals and only allowing the strongest to mate. In this video all we see is the fight, but if the male was suitably strong then they would have proceeded to mate. Females will mate with multiple males and any one nest may hold a mix of half brothers and sisters.