Rodney promoted Bickerton to the rank of post captain on 8 February 1781 and gave him temporary command of HMS "Invincible". It was in her that Bickerton took part in the Battle of Fort Royal, an action fought on 29 April 1781, off the coast of Martinique. Bickerton acquired his own ship, HMS "Russell", in May, before briefly transferring to "Terrible" but, finding her unfit, moved to the frigate, HMS "Amazon", in July. After service in the Leeward Islands and North American waters, Bickerton returned to England in "Amazon", arriving in Portsmouth in February 1782. In September, Bickerton was given the newly repaired HMS "Brune"; she was decommissioned in May the following year and Bickerton was without a ship until January 1787, when he commissioned HMS "Sibyl" and in her sailed for the Leeward Islands once more.