[3] The ship was designed with bows forward and astern in order to avoid the need to turn round at Calais, France.

[2] Costing about £70,000 to build,[9] she was designed by a Captain Dicey, who thought that she should be more stable therefore leading to less seasickness for her passengers.

[11] On her delivery voyage from Gravesend, Kent to Dover on 15 September 1874, trouble was experienced with priming of her boilers, necessitating a reduction to half-power, although a speed of 10 knots (19 km/h) was attained.

A protruding bolt on the Admiralty Pier at Dover caused some minor damage, which was quickly repaired.

Although her steering gear had failed, there was no difficulty in manoeuvering the ship, attributed to the fact that the engines drove each paddle wheel independently.

[16] Her lack of speed meant that she could not operate in connection with mail trains and she was not a success financially.

[17] Following his unsuccessful attempt at swimming across the English Channel on 12 August 1875, Matthew Webb returned to the United Kingdom on board Castalia.

[20] On 11 October,[21] the Prince of Wales travelled on board Castalia as part of his journey from London to India.

[24] In January 1876, the board of the English Channel Steamship Company agreed to an issue of £150,000 of shares paying a dividend of 7% in order to finance an improved version of Castalia.

Sir Charles Russell, MP stated that the South Eastern Railway (SER) had done everything in its power to obstruct the English Channel Steamship Company.

Lord Elcho stated that if the railway was sincere in its desire to improve communication with the continent (the stated aim of the bill), then it would run its trains to suit Castalia, rather than expecting the ship to run to suit its trains.

[29] Sir Edward Watkin was asked about this state of affairs at a shareholders meeting of the SER on 3 August.

Although her boilers were priming, an increase in speed of 2 knots (3.7 km/h) was achieved compared against similar power settings for the old paddle wheels.

[5] The English Channel Steamship Company was wound up by order of the Court of Chancery following a petition from Castalia's builders.

[36] A further four-hour trial run was made on 17 August 1878 when Castalia sailed from North Woolwich, having been laid up for seventeen months.

[38] On 24 October, Castalia rescued the captain of Ruth, which had sunk in the River Thames during a squall.

[39] In September 1881, Castalia was advertised to be sold the following month on the instructions of the mortgagees, Messrs Bailey & Ridley.

[5] The sale was advertised as taking place at the Captain's Room of the Royal Exchange, London on 20 October 1881.

[40] In May 1883, Castalia was sold to the Metropolitan Asylums Board for £5,500 and converted to a hospital ship with provision for 150 patients.