Couple who were stranded at sea share emotional conversation they had after realising they might not survive

A couple who were lost at sea for more than 40 hours have shared details about the terrifying ordeal, including what they said to each other when they realised they might not survive.

On the morning of 24 July, experienced scuba divers Nathan, 49, and Kim Maker, 44, set off from a beach in Freeport, Texas on a group diving trip with 16 other divers.

However, things went seriously wrong for the married couple when strong currents separated them underwater from the rest of the group at around 10.45am.

Nathan and Kim Maker were left stranded at sea when they became separated underwater from their diving group (Nathan Maker)

Nathan and Kim quickly swam to the surface and inflated their 'surface marker buoys' that are designed to make them visible from a distance.

"We were about 150 yards behind the boat, and they didn't see us," Nathan told the Daily Mail.

By the time an alarm was raised, the currents had swept them even further away.

Nathan and Kim then spent nearly two days lost at sea before finally being rescued by the US Coast Guard.

Since their rescue, the couple have opened up about the moment they thought they might die.

It was during their second night at sea that Nathan began to hallucinate about his dead father.

"Nathan has diabetes and takes medication for his heart," Kim explained. "We both knew that if one of us was going to go first, it would be him.

"If he died, I was supposed to cut the tether we'd made that was binding us together and just let him go.

The couple were forced to have the dreaded conversation of what to do if one of them died (WHAS11/ABC News New York)

"But I had no interest in surviving without him and I had a plan. As dark as it sounds, if Nathan had died, I was going to take off my diving gear, letting myself drown and go with him."

Nathan was equally emotional as they recalled the traumatic event.

"If either one of us had been out there alone, we wouldn't have made it," he said. "We didn't give up. We fought together. When I was weak, she was strong, and vice versa."

The couple said their optimistic outlook was vital to their survival.

"We were starting to get cold and shiver so we started doing little sprints of swimming to warm ourselves up," Nathan recalled.

"We tried to make a game of it. We were telling each other jokes, trying to keep our spirits up.

"My wife was singing songs that she remembered from when she was a little kid."

After a 36-hour search, the Makers were finally rescued after being spotted swimming in the sea by the US Coast Guard (US Coast Guard)

Almost two days after the couple went missing, they heard the sound of a plane flying overhead and, a short while later, a rescue boat came roaring towards them.

"We started hugging and kissing each other. I'm not exaggerating when I say those guys grabbed us from the grip of death and pulled us into that boat."

The rescuers gave them water and wrapped them in blankets, before rushing them to the US coastguard vessel.

"We were so weak they had to help us walk," Nathan recalled. "We got a medical check, showers. The coastguards gave us the clothes off their backs.

"They made us a bed but we couldn't sleep because we were so excited – all we could do was thank them profusely.

"The men and women of the coastguard are truly wonderful."