Wooden paddle steamer Dophin built James Lang, Dumbarton, 1834
117 grt, 73 nrt, 97 x 16 x 6.5 ft
Re-engined 1840 by Johnson & Co., Liverpool, 56hp.
Served in Clyde; as a Mersey Ferry; from Porthdinllaen [see below] and finally, from 1848, from Sligo.
More history.
Voyage Sligo to Irvine with oats, leaky and abandoned
Foundered 5 miles NNW of Fanad Light (Lough Swilly)
All crew saved in own boat.

Minor collision [from Gore's Liverpool General Advertiser - Thursday 18 October 1838]:
Case of Running Foul in the River. The information laid under the statute charged the defendent with having, on the 10th instant, "wilfully, negligently, and carelessly run the Woodside Ferry steamer Kingfisher against the Monk's Ferry steamer Dolphin, and damaged her: and further, that he had refused to pay the amount of the injury."

  Another mis-hap when Dolphin was carrying on the service after Monk was lost in early January 1843 [from Liverpool Standard and General Commercial Advertiser - Tuesday 17 January 1843]: Pwllheli Jan. 14. The steamer Dolphin, Jones, of Liverpool, is on shore on the beach at Portynllaen [sic], considerably injured.

[from Liverpool Standard and General Commercial Advertiser - Tuesday 19 December 1843]:
The traffic in pigs between Carnarvon and Liverpool this season has been so extensive, that upwards of three thousand head have been shipped by the steamer Dolphin alone.

[from Derry Journal - Wednesday 28 November 1855]:
  Loss of the Steamboat Dolphin. On Friday night[17 November 1855] last this vessel, the property of Moses Monds and Co., of this town, was lost whilst on her way from Sligo to Irvine in Scotland, with a cargo of oatmeal. It appears that whilst passing the Fannet[Fanad] Light off Lough Swilly head, she suddenly sprung a leak and shortly afterwards foundered. We are glad to state that all hands on board were saved. We understand that both vessel and cargo were insured. Sligo Independent.

Lloyd's List quotes her sinking 5 miles NNW of Fanad Light - at the western entrance to Lough Swilly.