I found this short note in The Musical Times. A lot could be said and written about Parry’ nautical interests, however this text gives a good indication of what the composer got up at sea!
Sir Hubert Parry's favourite recreation [was] yachting. ‘I suppose I shall be drowned some day,’ he says. (On repeating this remark to Mr. Dannreuther , he observes: ‘Well, what is the use of a Shelley  unless one follows his example ? ‘) ‘I was very nearly drowned,’ continues Sir Hubert, ‘when I was twelve years old, in coming from Nice to Marseilles. A little more obstinacy on my part, and I should have been pitched over into the Mediterranean and provided food for the sharks. I have been nearly drowned heaps of times. Once I went round the Isle of Wight in a gale, and nearly drove my skipper out of his wits. “You ain't been drowned yet,' he observed, 'but you've done your very best.”
I began yachting through having to live at Littlehampton for many years on account of my wife's health. I started with a 2-tonner, then followed a 7-tonner, now I have a 21-tonner, and I daresay I shall have a bigger yacht some day.’
The following is a characteristic boating story concerning the genial Director of the Royal College of Music. One day he was enjoying a very Elysium of happiness sailing all alone in a canoe in a very stiff breeze. He was capsized and had to swim about two miles to terra firma. But he would not lose the boat, and towed it ashore with the rope of the boat between his teeth, an operation which took nearly an hour and a half!
The Musical Times 1 July 1898 [with minor edits]
 Dannreuther Edward,Strassburg, 4 November 1844 – Hastings 12 February 1905. Aged 5 he was taken to Cincinnati, where he studied with F. L. Ritter and then later as a pupil of Richter, Moscheles and Hauptmann at the Leipzig Conservetoire. He arrived in London in 1863 as pianist; In 1872 he founded and conducted the London Wagner Society; wrote"Richard Wagner, His Tendencies and Theories" (London, 1873). He was also a minor composer. He was a Professor of Piano Music at the Royal College of Music from 1895 until his death. Dannreuther was a friend and imporntat influence on Hubert Parry.
 On 8 July 1822, Percy Bysshe Shelley drowned during a sudden storm whilst sailing from Livorno to Lerici in his schooner.