Sir Tom Jones has spoken of the frightening moment he prayed to God to save him when he got into trouble swimming off the shores of Mexico.

The Voice UK presenter said the incident happened during a barbecue with family and friends on a trip to Acapulco in the 60s. 

Jones told comedian Alan Carr on his Life's A Beach podcast that being a "schmuck" at the time, he wandered off from the group "like a fool" to take a dip. 

But he didn't realize the waters were shark-infested and he was completely unaware of the strong currents. It was only later that his friend told him they "never" go into the water. 

"Me, schmuck, thought just over this dune is the ocean... so I wonder off like a fool, and I look at the calm water and think it looks lovely out there," he said.

"I go through the breakers and start swimming out, then somebody comes looking for me, standing on the beach and I look at them and the fellas about this big."

He realized he was in trouble when he noticed he had been swimming but "hadn't moved an inch."

"I thought, this is it now," he said.

The legendary hitmaker told Carr that usually, he would take off his large cross necklace whenever he went for a swim, but for some reason that day he left it on. 

"I always used to take my jewellery off and put it in my man bag, for some reason I didn't. I put my hand on my chest and still had this big cross and chain on," he said. 

Noticing that he was still wearing his cross necklace, he touched it and called out to God. 

"I put my hand on it and said, 'God, I'm desperate here. What do I do?' I was going to give up. I thought I'd take a load of water in and say good night," he said.

"A voice came to me and said, 'If you think you can swim, now is the time to prove it.'

"So I start to head towards the beach, head down I go like the clappers. I'm caught in the breaker and I'm looking for the light to find what way is up, because I'm spun.

"Surely I'm going to be thrown on the beach and break my neck? The wave tossed me on to the beach." 

Carr then asked him if he was sure it was God speaking to him in that moment: "So, you think that was God, not a lifeguard with a megaphone?"

But Sir Tom, 80, was sure.

"Definitely, on my life," he said.

"Then I talked to real swimmers who said the undertow was taking you out to sea, you have to go left or right or you'll never make it. There's no way, you must have had some divine thing. It was not your time to go."