A field trip to Newhaven will be set up to test the hypothesis that “You cannot change one part of the coastline without affecting another”. New haven is a well established coastal port overlooking the English Channel.The exact suite to be investigated will be the stretch of coastline from Newhaven to Seaford and Birling Gap. Seaford is a smaller port a few kilometres from Newhaven. This site should be perfect to test the hypothesis with a wide enough area to make the findings reliable. This site has been chosen because a major alteration to the coastline, in the form of a harbour arm, which has been in place for over 100years. The harbour arm is located in Newhaven.This is a well established construction, and was a major change to the coastline. Over such a long period of time any changes to other parts of the coastline as a direct result of the harbour arm, should now have taken place. Investigations should reveal evidence of any changes affecting other coastlines, and establish reasons to test the hypothesis. At the end of the investigation sufficient data should have be accumulated to prove or disprove whether the building of the harbour arm at Newhaven has influenced changes along other parts of the coastline.Newhaven is a busy resort in the South of England, on the English Channel. Until the 16th Century there was no harbour at Newhaven, because the River Ouse reached the sea at Seaford. In 1579 a great storm diverted the river, and ‘Newhaven’ was the result. It soon became a thriving coastal town and shipping area. Newhaven was an extremely popular port in the 19th Century, for tourism as well as business. In 1847 the cross channel service from Newhaven to Dieppe in France began.The service began with paddle-steamers by way of transportation, and has been going ever since, cross channel ferries and freight vessels are in use today. Many large vessels frequently used the port for commercial activities, bringing money and work to the area. In the 1880’s the local authorities governing Newhaven decided that a harbour arm should be constructed. It was thought that a harbour arm would help solve problems arising in that particular coastal area, and there was a great economic reason for doing so.The harbour arm was built to slow down longshore drift, a coastal process which can cause many problems for a busy port or popular coastal resort. Longshore drift is the process by which sand and pebbles are transported along the coast by waves. In Newhaven’s case longshore drift occurs from west to east. This is due to prevailing south-westerly winds which cause the drift from west to east along the Channel coast. This coastal process was silting up the base of the River Ouse which frequently had to be dredged, at great expense to the local authority. Longshore drift is a major factor in the formation of all land forms of coastal deposition. The direction of longshore drift always has to be taken into account by local authorities when they are planning sea defence strategies, and protecting beaches to maintain tourism.Due to prevailing south-westerly wind longshore drift travels from west to east along the Channel coast.A harbour arm would allow the river Ouse to increase in depth, because longshore drift would no longer be able to push material into the estuary. This would allow larger ships to use the port without fear of running aground. The base of the River Ouse would no longer need dredging because of the silt build up. There would be an increase in the size and type of shipping using the port and allow the expansion of commercial activities. The area would thrive economically. Like most coastal areas, Newhaven attracted settlement and tourism, to build on this the port needed to be improved. With its cross channel ferry service and strong port links to mainland England, it soon became the main industrial centre of the district, and a base for many commercial operations. All this brought more employment to the area which created economic development. The area thrived economically.The definition of ‘Harbour’ is a place of refuge, to give shelter. The definition of ‘Arm’ is anything considered to resemble an arm in appearance, position or function. Putting these two definitions together describes and defines the type of construction a harbour arm is. It is a promontory constructed into the sea and reaches out like an arm. It withstands even the worst sea conditions. The Newhaven harbour arm was positioned on the Newhaven cliff side of the harbour. It stretches out into the open sea and then hooks towards the Seaford direction.During this investigation data will be accumulated to establish whether the building of the harbour arm has influenced changes along other part of the coastline. The intention will be to accept or reject the hypothesis that “You cannot change one part of the coastline without affecting another”. The investigation will present an illustration of the type of coastal process occurring in that area.Throughout the investigation various methods of data collection will be used. These will include slope profiles, pebble measurements, field sketches and photographic evidence. All of the data will be collated to form an overall picture, and eventual evaluation.