The Australian Maritime Safety Authority co-ordinated their rescue after it detected an unregistered 406MHz distress beacon off the coast about 8.45pm last night.

The beacon was traced to a vessel in distress about 1.5km west of South West Cape near Maatsuyker Island.

Police called the lighthouse keeper on Maatsuyker Island, who contacted the vessel's crew and determined their location through the vessel's onboard navigational equipment.

The vessel was drifting in seas of more than eight metres and winds of more than 100km/h.

AMSA's Essendon-based dedicated search and rescue aircraft from Victoria, a Tasmania Police helicopter and the Tasmania Police vessel Van Diemen from Hobart were activated.

The AMSA aircraft arrived about midnight and located the vessel and maintained radio contact with them.

The police helicopter was forced to return to Hobart, because of adverse weather conditions.

The Van Diemen crew saw the stricken boat about 4.10am this morning, within one kilometre of Maatsuyker Island and 500 metres of Walker Island.

The broken down vessel had drifted about 24km from when the distress beacon was first activated.

The police vessel deployed a rigid hull inflatable boat to rescue the sailors.

The people were rescued about 5am and were safely onboard the Van Diemen about 5.30am.