Porter had converted a captured vessel into Essex Junior, but the name overstated her usefulness in a frigate action. British intelligence had already established her armament and combat value. Phoebe and Cherub could therefore ignore her fire and concentrate on disabling Essex, the only American ship capable of threatening them. A second hull added little to the American force because its weapons could not influence the engagement.
Notable Point · 6:58-9:36
Essex Junior was too weak to alter the battle
The British knew Essex Junior's light battery posed so little danger that they concentrated entirely on Essex until the main frigate surrendered.