The skipper of a Coastguard boat who rescued two divers after they became separated from their boat in waters near Kāpiti, north of Wellington, says the scenario is the stuff of nautical nightmares.

The divers were dragged south in swift currents, but managed to swim to a nearby island and even had provisions to light a fire, alerting the Westpac Rescue Helicopter to their location.

Coastguard skipper Mark Davidson told Checkpoint police were alerted by the diver's partners - who were waiting on the diver's boat - that they had lost contact with the men about 5pm on Sunday.