Prior to the United States entering World War II, they had produced two ships of the Raven-class minesweeper for testing and evaluation.

From these two examples it was decided that the use of diesel-electric engines to power the ship and the minesweeping equipment, rather than separate geared diesel engines to propel the ship and diesel generators to energize the minesweeping equipment, would work better.

Originally designed with four 20 mm (0.79 in) Oerlikon cannons, some ships mounted as many as eight.

[3] Twenty of the original 32 ships ordered by the Royal Navy were delivered, with an additional two coming from the USN program.

[4] Eleven minesweepers of the Auk class were lost in World War II, six to direct enemy action including USS Skill, torpedoed by U-593.