She performed one whaling voyage for French owners before a British letter of marque captured her in 1803.

[5] However, despite the outbreak of the Napoleonic Wars and the end of the Peace of Amiens she went whaling in South African waters.

[1][6] By 25 September 1803, the letter of marque Scorpion was at Delagoa Bay on the east coast of Africa.

When Cyrus was sold in 1804, Lloyd's Register gave the name of the buyer as Mather & Co., a noted owner of whaling vessels.

Cyrus reported that the whaler Alexander arrived at St Helena on 26 March 1806 from New Holland with 1200 barrels sperm oil.

[3] Cyrus left on 1 September 1808 on her third whaling voyage, this time under the command first of "Walls", and then Paul West.

[3] Paul West was again Cyrus's master on 29 September 1810 when she left on her fourth whaling voyage.

[3] Enderbys sold Cyrus to "Thompson", who thus became her owner for her sixth and seventh whaling voyages.

British ships were then free to sail to India or the Indian Ocean under a licence from the EIC.

[12] Cyrus's owners applied for a licence to sail to certain ports in the East Indies under the provisions for whalers.

[2] Cyrus left on her sixth whaling voyage on 30 August 1814, with W. Davey (or Davies), as master, and with Peru as her destination.

[3] W. Davey (or Davy) was again Cyrus's master in 1816 when she left on her seventh whaling voyage.

[3] Cyrus's eighth voyage began on 26 August 1818 when Captain Hale (or Hall), sailed her for Peru.

[13][c] On 15 July 1821 Cyrus left again, on her ninth whaling voyage, still under the command of Captain Hall.

[3] The Register of Shipping gives her master as Hingston and her owner as Jarvis & Co.[15] In September 1831 she was at the Moluccas with 900 barrels.

[3] On 25 September 1841, Cyrus, Richard Spratly, master, and J. Staynes & W. Ive, owners, sailed on her 15th whaling voyage, again to Timor.

This gave rise to the Kema incident when several crew members deserted and Cyruseventually sailed, leaving them behind.

[3] Spratly sailed Cyrus on his fourth as her master and her 16th whaling voyage, leaving Britain on 16 May 1845.

[d] She was then at Batavia, Dutch East Indies, on 18 September, preparing to sail for the south seas.

[3] Lloyd's Register (1854) had an entry for Cyrus, giving her master as "Hensbrgh", her owner as W. Ives, and her trade as London-"M'lm'm".