Built as a harbour pleasure boat, by Lars Halvorsen & Sons of Sydney, Sea Mist commissioned as HMAS Sea Mist on 21 July 1941.
Miniature submarine M22 was first spotted at 3.50 am to the north of Garden Island. Channel patrol boats including Lauriana, Lolita, Sea Mist, Steady Hour, Yandra and Yarroma were by now actively searching for the submarines, while several of the warships in port prepared to put to sea rather than risk being torpedoed while at anchor. At around 5:00am Sea Mist entered Taylor Bay to investigate a possible submarine sighting and saw the conning tower of a submerging submarine. Sub Lieutenant Andrew commenced an attack with Sea Mist dropping 2 depth charges over the site where the submarine had last been seen. The second depth charge exploded close to Sea Mist causing damage to its engines and it was forced to break off the attack.
Further depth charges were dropped by Steady Hour and Yarroma between 6:40am and 8:30am. The attacks by all 3 vessels had effectively disabled M22 which now lay on the seabed at Taylor Bay. The miniature submarine’s 2-person crew, knowing that there was no hope of escape, died of self-inflicted revolver shots. M22 was later recovered from the seabed.
Following repairs to the damage to its engines Sea Mist returned to its routine duties as a channel patrol boat. In early March 1944 Sea Mist was transferred to the Naval Auxiliary Patrol (NAP) under the command of Skipper (NAP) Albert Askew and its name amended to its original Sea Mist. It was refitted in Sydney for duties as an Air/Sea Rescue vessel in northern Australian waters.
After arriving in northern Australian waters, Sea Mist proceeded to Melville Bay (near Nhulunbuy) for Air/Sea rescue duties and began supporting Allied air forces conducting operations against Japanese forces in New Guinea and the Netherlands East Indies.
In early January 1945 Sea Mist departed Melville Bay for Darwin and on 8 January, in inclement weather, struck a submerged object. Subsequent inspection, however, found no damage and it continued on to Darwin temporarily hampered by an oil leak in the port engine.
On 19 January Sea Mist was returned to the RAN with Skipper Albert Askew commissioned as an RANVR Sub Lieutenant. It conducted boom defence patrol duties in Darwin until 26 February 1945 when it departed, in company with the air-sea rescue vessel HMAS Steady Hour and the 3 masted former coastal trading vessel Alma Doepel, bound for Townsville and a major refit. While en route, the vessels stopped at Melville Bay to refuel and during this evolution Steady Hour caught fire and was destroyed, fortunately without loss of life.
Sea Mist subsequently arrived in Townsville on 7 April, however, the extent of the refit work package, which included the installation of 2 new engines, could not be conducted in Townsville without compromising other maintenance tasks. It was decided instead to conduct the refit in Brisbane where it arrived in late May and where it remained until the end of the war.
Sea Mist was towed to Sydney by the boom defence vessel HMAS Koala in October 1945. It was decommissioned on 9 November 1945 and sold back to Hope Bartlett in January 1946. Sea Mist was later on-sold and modified by various owners and is still afloat as of 2020, but looking very little like the original vessel.