by John Marshall, Royal Naval Biography — Bishop… (1823)
“ They were distinctly seen under water, particularly a large white mass of rock, in 41/2 fathoms, having from 5 to 61/2 fathoms round it. The shoal was traced in 7 fathoms, on detached rocks, near the edge of it, having deeper water between them. On the southern edge of the shoal, from S.E. to W., the depth increases gradually to 30 fathoms, at the distance of half-a-mile from the shoalest part. ”
