It’s a widely accepted fact that boats sink if they have too many people or too much weight on them. The same can be said for romantic comedies. If they focus on a central character, then it usually is smooth sailing. “Couples Retreat” tries the same journey with four different couples, but the film’s badly executed jokes only add deadweight to the plot.

“Couples Retreat” is about four couples taking a trip to Eden, a secluded tropical paradise and couples therapy retreat. They hope to relax and ignite lost sparks of passion with their significant others, only to find the couples therapy program is more regulated and frustrating than they anticipated.

The first couple, Dave (Vince Vaughn) and Ronnie (Malin Akerman), is a pair of traditional suburbanites immersed in the chaos of work, children and shopping for new bathroom fixtures. Joey (Jon Favreau) and Lucy (Kristin Davis) are high school sweethearts who married young and constantly try to sleep with other people. Shane (Faizon Love) is a recent divorcé who desperately tries to fill the hole his previous wife left. He dates Trudy (Kali Hawk), an energetic, 20-year-old party animal half his age. And finally, Jason (Jason Bateman) and Cynthia (Kristen Bell), the no-nonsense, white-collar couple that considers divorce because of their inability to have children.

The movie capsizes from its encumbering amount of characters played by many of the popular comedic film actors seen in the last five years. Some of the actors have made face time in “The Break-Up,” “Juno” and “Forgetting Sarah Marshall,” to name a few. The excessive amount of couples is unnecessary since they all undergo the same process of denial, realization and acceptance of their issues. There’s also the quintessential ending that leads up to four repetitious “kiss and make up” sessions.

The film delivers an excess of weak, unsavory stabs at humor. For starters, there is plenty of childish, sex-based potty humor. This is embodied during a scene when a Fabio-esque yoga instructor (Carlos Ponce) dry humps the cast in a Speedo while leading them through stretches and awkward poses.

The film fails where other comedies like “Zombieland” and “Extract” succeed. Where these films fully embody the exaggerated comedy theme, “Couples Retreat” seems disjointed. The movie’s themes of love and relationships are not fleshed out enough and are a recycled representations of the issues that plague many couples.

If “Couples Retreat” has one saving grace, it is the quirky island resort staff. They arguably exude much more personality than the main characters. The ringleader of the employees is Marcel (Jean Reno), the aloof, Zen-like master of the island. He has studied everything from Tai Chi to “The Art of War” for the sake of fixing relationships. His antics generate some of the funnier dialogue in the movie.

The peculiar island staff is not enough to keep “Couples Retreat” afloat. Even if they threw three of the couples and the empty humor over the side, the film would still  have just been an empty shell of a romantic comedy.

“Couples Retreat” was written by John Favreau, Vince Vaughn and Dana Fox and directed by Peter Billingsley.