The captain of Monday’s doomed Santa Cruz boat describes in a chilling distress call how all of his passengers are trapped below deck — “with no escape hatch.”

Audio of the harrowing 3:14 a.m. recording includes a Coast Guard operator first frantically asking for information on the emergency off the coast of southern California.

“What is the emergency? Over. … Conception, what is the emergency? Over!” the operator says, referring to the diving tour boat.

A man who later identifies himself as the captain responds, “On board a vessel on fire.”

“Your vessel is on fire? Roger. Are you aboard the Conception?” the Coast Guard worker asks.

The captain confirms he is from the craft and says, “There’s 33 people on board the vessel on fire. They can’t get off.”

The Coast Guard worker responds, “Roger. Are they locked inside the boat? Roger. Can you get back on board and unlock the doors so they can get off? Roger. You don’t have any firefighter gear at all, no fire extinguishers or anything?”

The captain’s reply is unclear.

The Coast Guard operator says, “Is this the captain of the Conception?”

“Roger,” the man says.

The Coast Guard worker asks, “Was that all the crew that jumped off?”

The unidentified captain replies, “Roger.”

The operator asks, “Is the vessel fully engulfed now?”

The captain replies, “Roger. And there’s no escape hatch for any of the people on board.”

The Coast Guard worker asks, “How far away are you from the boat right now?”

The captain’s answer is unclear amid the static.

“Are there any other vessels in that area that can help with firefighting?” the operator asks.

Only static can be heard on the recording.

The Coast Guard worker is then heard putting out a general distress call, saying it “received a report of a vessel on fire with 33 people, correction, 34 people, trapped below deck … Any vessel in the area that can rend any assistance, please do so.”

A man responds through the emergency radio channel, “I heard a mayday call there … I’m 15 minutes away from that location. Would I be of assistance in that time frame?”

The operator replies, “If you could respond, we would appreciate it. Also, if you have any firefighting gear, hose, anything like that, that would be great.”

Another nearby boat — the Grape Escape, which rescued crew members including the captain — is involved in another exchange with an emergency operator.

“Is the captain of the vessel on your vessel?” a Coast Guard worker asks the captain of the Grape Escape, who replies yes.

Heavy.com first reported on the audio.

There also was audio posted online that included a man screaming, “Mayday! Mayday! Mayday!” and “I can’t breathe!”

All five crew members including the captain were on the bridge at the time of the pre-dawn fire and escapted, authorities said.

Thirty of the 34 passengers aboard have yet to be accounted for. Rescue workers recovered four bodies near the ship Monday afternoon.