Diligent (or Petit Diligent[4]), was the Bengal Pilot Service schooner Tannah (or Tanna), that the Bombay Dockyard had launched in 1775 for the Bengal Pilot Service of the British East India Company (EIC).

Although Tannah is described as a pilot schooner, that may reflect her role rather than her sailing rig.

She was one of a number of pilot vessels that the Bengal Pilot Service operated to help East Indiamen and other vessels approaching the mouth of the Hooghly River.

[6] Within the year, the French brought Tannah to Île de France (Mauritius), converted her to a corvette, and recommissioned her under the name Diligent.

Diligent, Captain Macé, was present on 6 July 1782 at the Battle of Negapatam.