Females can mate with more than one male in a season. As a result, each nest can have embryos of different fathers. Female sea turtles can also store sperm so that consecutive nests can have embryos of the same father.

Female sea turtles usually nest at night to prevent predators and heatstroke. Some species, however, such as the olive ridley turtle and the hawksbill turtle can be found regularly nesting at day time! The nesting process can take from 45 min to 5h. A female sea turtle can nest several times during each nesting season and will make anywhere from 2 to 8 nests to maximize the number of eggs laid.
It is a huge effort for a female sea turtle to drag her body up the beach using only her flippers. During this ordeal, she can be easily disturbed and will sometimes abandon the nesting attempt, known as a false crawl.

Once she is above the high tide line, she first starts clearing an area of debris. She then creates a body pit to lie in comfortably before starting to dig the nest. Using her hind flippers, she digs a deep nest chamber, stopping only when her hind flippers cannot reach to pull any more sand from the beach.
During nesting, the female turtle enters a trance like state. She lays her eggs in batches of two-to-three at a time. The average nest contains between 80 and 200 eggs depending on the species, with smaller species laying more eggs.

Each egg is about the size of a ping pong ball. It has a yolk and is soft shelled to prevent it from breaking when dropped into the nest. The soft shell also allows the eggs to remain moist and exchange oxygen.
After all the eggs are laid, the female sea turtle fills in the hole with her hind flippers and packs down the sand. Finally, she will camouflage the nest by throwing sand backward with her front flippers. Once she is done, she will return to the water for a well deserved rest of 10-15 days!

After nesting season is over, females return to their feeding areas– generally nearshore (neritic) areas–to replenish their energy stores for the next reproductive season. This period typically takes more than a year, and in many cases, several years.