CASEY PHILLIPS: Just like its premise, “Couples Retreat” is basically a rainy day at the beach. All the right ingredients are there — the ocean, the palm trees, the rum drinks — but extenuating circumstances have dampened the fun.

The problem is that “Couples Retreat” has really funny people — Vince Vaughn, Jon Favreau and Jason Bateman — paired with a plot (written by Vaughn, Favreau and Dana Fox) that’s bland and doesn’t provide opportunities for them to flex their comedic muscles.

A shark-feeding debacle and an extended yoga session that’s basically five minutes of soft-core porn are memorable moments, but when the tone predictably shifts to sappily romantic, the scenes have all the comedic agility of a soggy wool sock.

Fortunately, the movie isn’t a complete wash. The romantic pairings, particularly Vaughn and Malin Akerman and Kristin Davis and Jon Favreau, are convincingly loving and abrasive, and the early scenes are a gas.

HOLLY LEBER: Like a lot of mainstream romantic comedies that feature very funny people who are more in their element in something more offbeat and quirky, “Couples Retreat” struggles to stay afloat. Most of the best moments are given away in the trailer, leaving the rest of the time to be filled with a lot of sex-related gags, therapy claptrap and what essentially is a commercial for “Guitar Hero.”

The actors have a nice chemistry, for the most part. The presence of Kali Hawk as Trudy, a barely legal brat who has hooked up with recently divorced Shane (Faizon Love) is skin-crawlingly uncomfortable. There is, under no circumstance, any reason to ever address your lover as “Daddy.” Blecchhh.

CASEY: “Couples Retreat” is director Peter Billingsley’s second film, his first since 1994’s “Sacred Fire.” His untried return to the chair is apparent in the movie’s rough seams and inconsistency. He seems to have placed lot of emphasis on pumping up humor in the early scenes but allowed the movie to lose focus halfway through.

HOLLY: There simply isn’t enough balance of thoughtful and funny. In particular, Vaughn and Akerman play a couple who’ve gotten so caught up in day-to-day life that they barely recognize how little time they make for each other or that they’ve fallen into a pattern of taking each other for granted. Or Bateman’s character being so obsessed with doing things perfectly that he forgets to just enjoy being with his wife (Kristen Bell). A lot of people will probably be able to recognize themselves and their partner in one or more of the couples, but with four pairs, there’s not enough time to address the issues fully and have time for humor. Therefore, everything gets watered down.

CASEY: Or rained out. Don’t give up on the metaphor, Holly.

HOLLY: Indeed, Casey. Rained out.