HMS Howe was originally the teak-built Indian mercantile vessel Kaikusroo that Admiral Edward Pellew bought in 1805 to serve as a 40-gun frigate. In 1806 the Admiralty fitted her out as a 24-gun storeship and renamed her HMS Dromedary. She made numerous trips, including one notable one to Australia when she brought out Lachlan Macquarie and his family to replace William Bligh as governor of New South Wales. Later, she became a prison hulk in Bermuda. Her most recent contribution, however, is as the source of a rich archaeological site.

Built in 1799 in Bombay, Kaikusroo was a so-called Bombay "country ship". As such she engaged in trading voyages on the Malabar Coast and to the Malacca Straits.

Between 1801 and 1802 she served under charter from the East India Company to the British Government as a transport ship in the British military expedition from India to Egypt and the Red Sea. Captain Thomas Hardie was appointed commodore of the fleet of country ships.

During the period of the charter her owner was the Parsi shipbuilder Sorabjee Mucherjee. His guarantor was the Bombay merchant Charles Forbes, who served also as Kaikusroo's agent); her captain was Colin Mackenzie. At the time of her charter, Kaikusroo was valued at Rupees 275,000.

Admiral Pellew purchased Kaikusroo from Sorabjee Mucherjee in Bombay in April 1805 for £43,000. His aim was to use her as a 40-gun frigate. Pellew commissioned her as the Howe under Lieutenant Edward Ratsey (acting). Captain George Cockburn replaced Ratsey and she sailed from India in May with Marquis Wellesley, the departing Governor-General of India, and his suite embarked. Howe and Wellesley, coincidentally, stopped at Saint Helena and stayed in the same building to which Napoleon I of France would later be exiled. Howe arrived at Portsmouth on 7 January 1806. She then moved to the Downs en route to Woolwich Dockyard. She was paid off in February.

There, on 24 February, the Admiralty ordered her converted into a storeship of 24 guns. By March 1806 Howe was embarking stores and she sailed from Portsmouth 14 May under Captain Edward Killwick for the Cape of Good Hope. While she was away the Admiralty recommissioned her on 6 August 1806 and renamed her Dromedary. However, the order to rename her Dromedary seems to have taken a long while to take full effect.

She was ordered to sail from the Cape of Good Hope to Buenos Aires where she met up with Sir Home Popham's forces on 28 September. On 3 February 1807 took part in the Battle of Montevideo where she had four men lightly wounded.

Howe, under Captain Killwick, returned to Great Britain in August 1807. She brought with her the prize Diana. Diana had been built in Boston and sold to a Spanish merchant in Monte Video who had planned to use her as a privateer against the British. Diana was carrying hides, copper, tallow, Peruvian bark, furs, horns, ostrich feathers, Vigonia wool, Spanish wool, ebony, goat skins, deer skins, etc. The newspaper report valued the vessel and cargo at £40,000.