A lagoon is a shallow body of water separated from a larger body of water by barrier islands or reefs. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. There is an overlap between bodies of water classified as coastal lagoons and bodies of water classified as estuaries. Lagoons are common coastal features around the world.

Lagoons are shallow, often elongated bodies of water separated from a larger body of water by a shallow or exposed shoal, coral reef, or similar feature. Some authorities (such as Nybakken) include fresh water bodies in the definition of "lagoon", while others explicitly restrict "lagoon" to bodies of water with some degree of salinity. The distinction between "lagoon" and "estuary" also varies between authorities. Davis restricts "lagoon" to bodies of water with little or no fresh water inflow, and little or no tidal flow, and calls any bay that receives a regular flow of fresh water an "estuary". Davis does state that the terms "lagoon" and "estuary" are "often loosely applied, even in scientific literature." Kusky characterizes lagoons as normally being elongated parallel to the coast, while estuaries are usually drowned river valleys, elongated perpendicular to the coast. When used within the context of a distinctive portion of coral reef ecosystems, the term "lagoon" is synonymous with the term "back reef" or "backreef", which is more commonly used by coral reef scientists to refer to the same area. Coastal lagoons are classified as inland bodies of water.

John Randal Kleiser (born July 20, 1946) is an American film director and producer, perhaps best known for directing the 1978 musical film Grease.

Kleiser was born in Philadelphia, Pennsylvania, the son of Harriet Kelly (née Means) and John Raymond Kleiser. He was raised in the Pennsylvania Dutch community in Lebanon, Pennsylvania.

Kleiser has directed several feature films, including Grease (1978), The Blue Lagoon (1980) with Brooke Shields, Summer Lovers (1982) with Daryl Hannah, Grandview, U.S.A. (1984) with Jamie Lee Curtis, Flight of the Navigator (1986), featuring the first use of digital morphing in a film, Big Top Pee-wee (1988), White Fang (1991) and Honey, I Blew Up the Kid (1992).

In London, Kleiser directed the comedy Getting It Right (1989), starring Lynn Redgrave, Helena Bonham Carter, Jane Horrocks and Sir John Gielgud. In 1996, he wrote and directed It's My Party, starring Eric Roberts, Gregory Harrison, Lee Grant, Bruce Davison and Marlee Matlin. As a writer-producer, he was responsible for the surfing film North Shore (1987) for Universal Pictures. He also directed the thriller Shadow of Doubt (1998) with Melanie Griffith and Tom Berenger. Working in 70mm 3-D, he directed Honey, I Shrunk the Audience (1995) at the Disney Theme Parks in Anaheim, Orlando, Tokyo and Paris. His television films include The Boy in the Plastic Bubble (1976) with John Travolta, the Emmy-Award-winning The Gathering (1977) and Dawn: Portrait of a Teenage Runaway (1976).

Brooke Christa Shields (born May 31, 1965) is an American actress and model. Some of her better-known movies include Pretty Baby and The Blue Lagoon, as well as TV shows such as Suddenly Susan, That '70s Show and Lipstick Jungle.

Brooke Shields was born in New York City to Frank and Teri Shields (née Schmon), who divorced several months after she was born.

Through her father's side, she has Italian, French, Irish, and English roots, along with high social position and relations to nobility. Her paternal grandmother was the Italian princess Donna Marina Torlonia. Shields was raised in the Roman Catholic faith. She has two stepbrothers and three half-sisters.

When Shields was five days old, her mother openly stated she wanted her to be active in show business, "She's the most beautiful child and I'm going to help her with her career."

For her confirmation at the age of 10, Shields adopted her middle name, "Camille". While attending high school, Shields resided in Haworth, New Jersey.

When she was 12 years old, Shields played a child prostitute her age in the 1978 film Pretty Baby. Eileen Ford, founder of the Ford Modeling Agency, said of Brooke Shields: "...She is a professional child and unique. She looks like an adult and thinks like one."