Robert Jennings, 68, drowned in Pawley's Island, South Carolina last month.
The new bond Jennings' family has formed with the good samaritan on the beach started with a phone call just minutes after Robert was pulled from the water.
"We were outside at the time and when we came back in the house we had a message that he had helped try to resuscitate my brother, " said Robert's brother Stuart Jennings.
The man on the phone was JR Rusgrove, and he kept calling that day to alert the family of the situation and make arrangements for Robert's car to be returned to Danville.
But the correspondence didn't stop there.
"I didn't want to be intrusive. It was more of a, 'I'm sorry, is there anything I can do?' and it just blossomed, " Rusgrove said.
Through Facebook and texts - they started talking everyday, and JR soon learned that he and Stuart were kindred spirits.
"Even if this situation had not happened, Stuart's the kind of gentleman that if I ran into him, we would have become friends outside of that, " Rusgrove said.
Rusgrove owns a Connecticut restaurant where he named a special menu item for Stuart's late brother. The Jennings family also sent him Robert's military dog tags that Rusgrove now wears side-by-side with his own.
Stuart says they hope to meet each other face-to-face some time soon.
"I texted him jokingly yesterday saying, 'What if we can't stand each other when we get together?' He said, 'No way that's going to happen. We're brothers from different mothers,'" Stuart said.
In the meantime Rusgrove says he feels a special responsibility to keep Robert's memory alive.
"I was here for a reason. The timing is the timing and I was person to be there, and I'm glad that it was me," said Rusgrove.