There was high drama on the rough seas, we’re told, after a “Real Housewives of New York City” pleasure cruise ended with the cast awash in vomit and fearing for their lives as their boat caught fire and started sinking.

Seagoing sources tell Page Six that the ladies of the Bravo reality show were preparing for a day of sunning themselves on a luxury yacht during a visit to Cartagena, Colombia — but things sank quickly into chaos after they realized they’d been booked onto an old, decrepit vessel.

“Once they were ushered on board, the boat couldn’t even move. The anchor got stuck, so the crew had to saw the anchor off before they could sail anywhere,” said our loose-lipped landlubber.

“When they got out to sea, the engine caught fire. It was a huge blaze and the crew was fighting to put it out. They didn’t have a fire extinguisher nor did they speak English,” we’re told.

Adding to their watery woes, we’re told the sea was so rough that “the seats and other things on board that weren’t nailed down started flying about.” The boat was taking on water, “and there were only two or three life jackets for everyone on board,” including the film crew.

The cast, we’re told, mustered a characteristic “Real Housewife” response. “They all thought they were going to die and they were hysterical,” we’re told. “Bethenny [Frankel], Ramona [Singer] and Dorinda [Medley] were soaked and screaming hysterically, Carole [Radziwill] and Tinsley [Mortimer] were literally throwing up from seasickness. They were far out to sea and they thought they were going down like the Titanic.”

They were eventually rescued by a passing boat. But we’re told the “Housewives” were all so traumatized by the experience that Bravo has offered them counseling.

A Bravo rep said, “‘The Real Housewives of New York City’ cast was recently on a boat in South America and encountered turbulent water. Thankfully, everyone is fine and was able to continue their vacation as planned. The safety of our cast and crew is paramount and, to that end, we are doing a full investigation.”