The alarm was raised when the companion of the stranded man waded back to Staithes from a spot called Short Sand half a mile north of Staithes.
As the lifeboat located the casualty, two members of the RNLI volunteer crew swam ashore with a rope from the lifeboat.
The man was successfully helped from the rocks back to the boat and transferred back to the Staithes RNLI boathouse.
The two men, both from North Yorkshire, had set off with the intention of exploring a disused tunnel which opens onto the shore and was once part of the old Boulby alum works.
They were wet and cold from their ordeal but unharmed.
Sean Baxter, Deputy Launch Authority at the station, said: “We cannot emphasise strongly enough how important it is to know the tide times before walking on the foreshore on either side of Staithes.
“And to let people know where and when you are going.
“These are very dangerous stretches.”