I went thru in ‘73 on a geo/exploration survey boat. The waters approaching were about 60 feet deep. Then plunge suddenly to over 300 feet as we steamed thru the old volcanao caldera area betwen the 3 outer surviving isles.
There was one small coconut tree that had sprouted on the solid black beach of Anak K. The new cone was only about 100” high then. Solid black from the beach to the lightly smoldering top.
[I went thru in 73 on a geo/exploration survey boat.]