An American naval captain, ordered to take his ship out of Boston Harbour to eliminate a pair of Bermudian privateering vessels, which had been picking off vessels missed by the Royal Navy, returned frustrated, saying the Bermudians sailed their ships two feet for every one of ours. The only attack on Bermuda during the war was carried out by two sloops captained by a pair of Bermudian-born brothers (they damaged a fort and spiked its guns before retreating). It greatly surprised the Americans to discover that the crews of Bermudian privateers included Black slaves, as, with limited manpower, Bermuda had legislated that a part of all Bermudian crews must be made up of Blacks.