A frustratingly not-terrible action thriller.
I had the feeling, watching "Mermaids," that it was originally headed in another direction. The material is "funny" instead of funny, and we don't laugh so much as we squirm with recognition and sympathy. It's a story told by a teenage girl whose mother avoids becoming known as the town tramp only because she changes towns so often. In the movies, eccentric parents can be palmed off as colorful originals. In life, especially to an adolescent, they can be excruciating embarrassments.
The mom in "Mermaids" goes by the name of Mrs. Flax, and is played by Cher. Not only played by Cher, but in an eerie sense played as Cher, with perfect makeup and a flawless body that seems a bit much to hope for, given the character's lifestyle and diet. Mrs. Flax has a personality trait that leads her to seek doomed love affairs with hopeless men, and then move to another town when her life crashes down around her. Little attempt is made to present her as a plausible character; this is one of those movies sidetracked by the David Lynch Syndrome, in which characters exhibit a tacky trait of consumerism that is exaggerated out of all proportion (the meals served by Mrs. Flax, for example, consist entirely of artistic arrangements of "fun foods").
She has two daughters; a teenager, Charlotte (Winona Ryder), and a grade-schooler, Kate (Christina Ricci). As the movie opens, Kate is practicing her swimming, and will eventually see if she can match the world record for holding her breath underwater. That supplies one of the movie's many clues to the symbolism of its title, as well as suggesting the desperation Mrs. Flax inspires in her children. The older daughter, Charlotte, has been driven nearly mad by her mother's incessant moves (18 by last count). She's never gone long to the same school, or made many friends, or experienced much normal life outside the hothouse of Mrs. Flax's fevered existence.
After yet another romantic disaster, the family moves again, to Massachusetts, where Charlotte makes friends with a young man named Joe (Michael Schoeffling) who has some kind of handyman job at a Roman Catholic convent which is just over the way. Charlotte is rather attracted to the nuns, to their quiet ways and cheerful encouragement, but she is more attracted to Joe, who perhaps possesses the secret of exactly what it is adults do when they're alone - what her mother does with all those men, for example.