This photo shows the likely location of Captain Harville's cottage. I have it on good authority - some years ago I did a little map for Maggie Lane's fascinating book - Jane Austen in Lyme. The year it came out my husband and I went on a Jane Austen Society conference to Lyme - I remember meeting quite a few people who'd come along from JASNA. I'm sure you'd agree we had a lovely time! I took the book with me on my travels this time - it was invaluable for finding my way around, and is full of the interesting history of Lyme along with Jane's connections to the place. You can order it from the Jane Austen Society here in the UK.
The building looks modernised and is now a cafe but I've included a photo below which shows the buildings next to it which look far more in keeping with the sort of architecture that Jane might have seen. The Royal Standard Inn is several hundred years old - on the first blustery day I sampled their fish soup which was delicious. At the front they have a garden overlooking the sea where I enjoyed a crab sandwich the next day watching the world go by in the sunshine.
Last, but by no means least is the passage from Persuasion to go with the pictures.
The party from Uppercross passing down by the now deserted and melancholy-looking rooms, and still descending, soon found themselves on the seashore; and lingering only, as all must linger and gaze on a first return to the sea, who ever deserve to look on it at all, proceeded towards the Cobb, equally their object in itself and on Captain Wentworth's account: for in a small house, near the foot of an old pier of unknown date, were the Harvilles settled. Captain Wentworth turned in to call on his friend; the others walked on, and he was to join them on the Cobb.
Here's a further passage giving a description:
On quitting the Cobb, they all went indoors with their new friends, and found rooms so small as none but those who invite from the heart could think capable of accommodating so many. Anne had a moment's astonishment on the subject herself; but it was soon lost in the pleasanter feelings which sprang from the sight of all the ingenious contrivances and nice arrangements of Captain Harville, to turn the actual space to the best possible account, to supply the deficiencies of lodging-house furniture, and defend the windows and doors against the winter storms to be expected. The varieties in the fitting-up of the rooms, where the common necessaries provided by the owner, in the common indifferent plight, were contrasted with some few articles of a rare species of wood, excellently worked up, and with something curious and valuable from all the distant countries Captain Harville had visited, were more than amusing to Anne: connected as it all was with his profession, the fruit of its labours, the effect of its influence on his habits, the picture of repose and domestic happiness it presented, made it to her a something more, or less, than gratification.
Captain Harville was no reader; but he had contrived excellent accommodations, and fashioned very pretty shelves, for a tolerable collection of well-bound volumes, the property of Captain Benwick. His lameness prevented him from taking much exercise; but a mind of usefulness and ingenuity seemed to furnish him with constant employment within. He drew, he varnished, he carpentered, he glued; he made toys for the children, he fashioned new netting-needles and pins with improvements; and if every thing else was done, sat down to his large fishing-net at one corner of the room.