Of special interest on this survey are the forts on Mud Island, Red Bank and further south at Fort Billings, and the location of the Chevaux de Frizes' (sunken sharpened stakes with metal tips) which were designed to force ships under the guns of the adjacent forts.  This chart also shows the position of the British ships as they made their way up the river clearing it from the threat of American land and water defences.

Lieutenants Hunter and Knight were part of a team of surveyors and hydrographers who worked closely together at this time, charting the important rivers of the Middle States.  These Middle States were extremely valuable to both the Colonial powers and to the invading British forces as they afforded such good access into the interior.  Captain Andrew Snape Hammond summed the situation up extremely well when he wrote 'on account of the Navigable Rivers of this Country, there is no part of this Country, there is no part of the continent where ships can assist land operations more.'  He was writing of the Chesapeake at the time but he might just as well have been writing of the Delaware.  The principle was the same. 

Hammond had, himself, reconnoitred and surveyed the river between March and May of 1776 (see Heritage Charts A302) and had reported the state and position of rebel defences to Admiral Richard Howe and to his brother General William Howe before they set-out on their campaign in July 1776 to capture Philadelphia (see also Heritage Charts A205).  As history would have it, General Howe's decision to turn British attention south, to capture Philadelphia after securing New York, rather than pushing North to join with General Burgoyne in Albany, ultimately proved fatal to the British campaign to retain their American colonies.  Howe’s decision to attack Philadelphia by sea rather than to press through by land from New Jersey only served to take the pressure off Washington's retreating army, giving them a valuable month with which to regroup.