5.6 km (3.5 mi) NE of Ugaiushak Island and 8.9 km (5.5 mi) S of Cape Kuyuyukak.
HistoryNamed for a Third-Order geodetic control station "Radial" set atop the island.
Aiugnak Columns, Logan Reef, Toee Reef,
Bays:Chiginagak Bay, Nakalilok Bay,
Capes:Cape Kuyuyukak, Cape Providence,
Islands:Central Island, Cupcake Island, Derickson Island, Devils Finger, Radial Island, Ugaiushak Island,