Diver found alive, cold, in Tas northeast

A missing diver has been found alive on a remote Tasmanian island after spending five hours in the water, and swimming to save his life.

The 32-year-old man was reported missing while diving near Waterhouse Island, off Tasmania's northeast, on Thursday afternoon.

A search vessel spotted the man on the shore of the barren island about 8pm.

"He had surfaced out of sight of his boat and had to make his way into the shore," Tasmania Police said in a statement.

The diver was suffering from mild hypothermia, they said and has been taken to the Launceston General Hospital.

The search had involved boats, the rescue helicopter and quad bikes along the shore of the Tasmanian mainland.