The pair had been playing at Cresswell Scars, a section of rocks on the edge of Druridge Bay sands, when the speed of the incoming tide caught them and their dog out, cutting off their escape route back to the shore.
A worried adult with the children realised the danger the youngsters were in and contacted the coastguard.
Within minutes of receiving the call at 6pm last Friday, Newbiggin RNLI's Atlantic 75 lifeboat CSMA 75th Anniversary was on the way to the scene.
On arrival, the group were spotted on the diminishing rocky area and were carried to the lifeboat before being taken ashore and checked by coastguards from Newbiggin.
Jimmie Dawson, helmsman on the lifeboat, said: "On arrival at the rock edge, the children were clearly frightened by the rising water so Jeff Brown and Paul Davison, who were the other members of the rescue team, quickly jumped into the sea and carried the two children onto the lifeboat.
"The children's signs of despair quickly ebbed away."
Newbiggin Lifeboat press officer Richard Martin praised the quick response of the rescue teams.
He said: "Whilst the group had been playing on the rocks with an adult nearby, the rapidly flowing tide caught out all of them.
"It is important to appreciate that the tide flows into these areas very quickly and the outcome, but for the actions of the lifeboat, could have been much more different.
"I urge the public to be aware of the SAFE message whilst on the beach."
The SAFE message is:
- Spot the dangers
- Always go with a friend
- Find and read the safety signs and flags
- Emergency? Stick your hand up and shout, tell a lifeguard or dial 999/112 for the coastguard.
More RNLI beach safety advice is also available at
www.rnli.org.uk/beachsafety