Apparently Darwin never went snorkeling

It is excusable to grow enthusiastic over the infinite numbers of organic beings with which the sea of the tropics, so prodigal of life, teems; yet I must confess I think those naturalists who have described, in well-known words, the submarine grottoes decked with a thousand beauties, have indulged in rather exuberant language.

Charles Darwin, The Voyage of the Beagle (London: John Murray, 1913 reprint ed., ch. XX, p. 487