Samuel Gurney Cresswell joined the Royal Navy and served as a lieutenant on board H.M.S. Agincourt, the flagship of Sir Thomas Cochrane, Commander-in-Chief of the East India and China station. Between 1845 and 1847, he distinguished himself in several actions against pirates in Borneo and Brunei.

Meanwhile Sir John Franklin was leading an expedition in search of the North-West passage, a navigable route between the Atlantic and the Pacific oceans. Franklin had sailed from Greenhithe on 19 May 1845 with 129 officers and men aboard the Erebus and Terror, both fitted out with state-of-the-art equipment. The ships passed from the Atlantic through the Davis Strait into Baffin Bay and were last seen on 26 July at the entrance to Lancaster sound, moored to an iceberg.

In 1848 Lieut. Cresswell volunteered for Arctic service and joined the Investigator as mate under Captain Bird. His first voyage was part of Sir James C. Ross' unsuccessful search for Franklin. He returned in November 1849 and almost immediately volunteered to rejoin the Investigator, now under the command of Captain Robert John Le Mesurier McClure (1807 - 1873). They began their search from the Pacific coast of America, travelling eastwards via the Bering strait. After nearly four years of fruitless searching, McClure had to abandon Investigator, trapped in the ice of Mercy bay just north of Banks island. His party was rescued by two ships at nearby Melville island but these also became trapped. In desperation he sent Lieut. Cresswell and a sledging party across the frozen ocean to Beechey Island with despatches for the Admiralty. By an incredible stroke of luck they encountered the Phoenix under the command of Captain Inglefield, who brought them back to Scotland. Thus Lieut. Cresswell's party were credited with being the first to traverse the North-West passage. In 1854 Captain McClure was awarded a knighthood for his leadership.

On 26 October 1853 King's Lynn welcomed Lieut. Cresswell with a lavish banquet in the Assembly room, tickets 1 guinea each. The Town Clerk read out a 'Congratulatory Address' and the Mayor, Lionel Self, presented him with a copy on an illuminated scroll of vellum to which the Corporate seal was attached by a golden cord. Lieut. Cresswell returned his thanks and regaled his audience with some of the hardships which he had suffered whilst leading his sledging party across the ice:

'We used to travel all night, about 10 hours, and then encamp, light our spirits of wine, put our small kettle on it to thaw the snow water, and after we had our supper - just a piece of pemmican and a glass of water - we were very glad to get in, after smoking our pipes ("Bravo," and laughter). The first thing we did after pitching the tent was to lay a sort of macintosh cloth over the snow. On this would be a piece of buffalo robe stretched. Each man and officer had a blanket sewed up in the form of a bag, and this we used to jump into, much the same as you may see a boy in a sack (laughter). We lay down, head and feet, the next person having his feet to my head, and his head to my feet, just the same as herrings in a barrel (laughter). After this we covered ourselves with skins over the whole of us, and the closer we got the better, as there was more warmth (laughter).'

The government gave up the search for Franklin in 1855 when it was discovered that the survivors had attempted to reach the Hudson's Bay Company's settlement. Lady Franklin was not satisfied and organised another search. The fate of the expedition was finally revealed in the spring of 1859. The Erebus and Terror had all but completed the navigation of the North-West passage and Franklin was entitled to the honour of its discovery.