At the end of the war, a transport vacuum arose when the Ministry of Shipping withdrew the wartime service between St Mary's and Penzance.

[6] The new ferry, built to carry 400 passengers and cargo, was launched on 17 November 1925 and named Scillonian by Mrs. A.A. Dorrien-Smith of Tresco Abbey.

Due to the number of tidal currents which meet off Lands End, and the need for a shallow draught to allow access to the Islands, the sea journey to Scilly can be rough.

[10] At the Annual General Meeting in September 2010, the following corporate figures were published: During the previous fiscal year, Steamship Company craft had carried 73,000 passengers to Scilly by air and sea.

In May of the same year, the Isles of Scilly Steamship Company began proceedings for a Judicial Review of the planning decision.

The actions of the Steamship Company were widely condemned by businesses, residents, and visitors to Penzance and the Isles of Scilly.

The planning application was successful and the new heliport was built, with the new Penzance Helicopters service starting flights to St Mary's and Tresco in March 2020.

[14] Following the objection to the Penzance Heliport plans, in February 2018 the Isles of Scilly Steamship Company announced its own helicopter service operating from Land's End, to begin in May 2018.

[17] In early 2007, press reports indicated that Cornwall County Council was expected to approved plans for the construction of a new roll-on/roll-off replacement ferry at a cost of £17.5 million.

[18] This plan (named in its late stages as Option A) was halted because of local opposition to both the built elements of the scheme and the vessel design.

In May 2016, the Steamship Company acquired the Mali Rose, a Norwegian freight ship that was expected to replace the smaller and older Gry Maritha in the autumn of that year.

[19] A £42 million fleet development programme was revealed in April 2023, including the building of Scillonian IV and two new freight vessels, to be in service by March 2026.

She departs Penzance at 9.15am and returns from St. Mary's at 16.30pm, although these times may differ on certain dates due to tidal conditions, school holidays, and other events.