Oliver, F6EPN provides today’s DX Shoebox picture. It’s from 1979 when the 1S1DX team operated from Barque Canada Reef, Spratly Islands. There’s more info on this DXpedition found here
Regarding Barque Canada Reef, here’s an interesting link all about it. Vietnam now “controls” the reef / rocks (since 1987) but its sovereignty is claimed by the nearest countries; China, Taiwan and Malaysia.
Highest rocks are 4.5 m high, at SW end. Much of reef is above water at high tide. Some sandy patches. 18 miles long. Vietnamese military structures were recently upgraded.