The small coastal steamship Dinnington was built to the order of Humble and Thomson Ltd of Newcastle and launched on 12th July 1873 from the yard of Coulson, Cooke and Co Ltd of Wallsend (Yard No.5). She measured 159.0′ x 21.4′ x 12.2′ and her tonnage was 366 gross tons, 236 net tons. She was powered by a single compound steam engine by Pattison and Atkinson of Newcastle delivering 50 registered horse power.
For the next quarter century she passed through the hands of various owners operating mainly on the east coast of the UK. In 1901 she was purchased by her final owners, Cuthbert Wilkinson and Thomas Alexander of Sunderland, and continued to ply her east coast trade. Later that year she grounded on the submerged end of Portland Breakwater while on a voyage from Plymouth to Goole. She was beached to avoid sinking and later refloated and repaired.
On her final voyage, under the command of master James Muir, she departed from St Davids in the Firth of Forth bound for Stornoway with a cargo of 450 tons of coal at 6pm on 15th February 1906. Muir had a crew of ten men under his command. By 8pm the following day the ship was abreast of Duncansby Head where she encountered a strong westerly gale. After battling the weather until they were near Stroma, the deteriorating weather and the prospect of a passage in the dark through the treacherous Pentland Firth forced the skipper to change his plans and head for the shelter of Longhope to let the storm pass. He ordered the course changed to north magnetic heading straight for Cantick Head on Orkney calculating that this would take the Dinnington west of Swona and towards the entrance to Hoxa Sound. The difficult night time transit with the tide sweeping through the Pentland Firth and the narrow channel between the islands of the firth was going well until, around 9:45, Muir noticed they were heading too close to Cantick Head itself and ordered a slight course change to take them east of the headland. At this point a heavy snow squall hit the area reducing visibility to almost nil. The timing was critical. As they peered into the darkness, suddenly a shoreline appeared directly ahead of the ship. James ordered helm full to starboard but it was too late. The Dinnington ran hard aground on the Point of the Pool, Switha. Almost immediately, bumping heavily on the rocks in a huge swell, the foremast crashed over taking most of the rigging with it. Minutes later the ship broke in two near the stokehold bulkhead and the forward part of the ship disappeared.
The ship was breaking up fast and skipper James ordered his men to put on their lifejackets to be ready to abandon ship. As they readied the lifeboat a huge wave hit the ship washing the lifeboat overboard with two of the men attempting to launch it. Thankfully they managed to scramble aboard the boat. Sadly two other men, probably swept overboard by the same wave, were lost. The rest of the crew boarded the lifeboat and, after a few minutes delay to try to locate the two missing men, headed for shore. Almost immediately they hit a rock and capsized. The crew were thrown into the boiling surf but they all managed to reach the safety of the rocky Switha shoreline. They were later picked up by a yawl from the island of South Walls and taken to Flotta.
The subsequent enquiry did not blame James for the loss of his ship but declared that he had made an error of judgement in heading for Longhope rather than turning back into the lea of Duncansby Head to shelter from the storm.