The earliest measure of defence undertaken by the Naval Air Service was the institution of a coastal patrol for the whole of the East Coast, from Kinnaird's Head, in Aberdeenshire, to Dungeness, between Dover and Hastings. This was ordered by the Admiralty on the 8th of August. The Royal Flying Corps, or rather, such incomplete squadrons of the Royal Flying Corps as were not yet ordered abroad, undertook the northern and southern extremes of this patrol, that is to say, the northern section between the Moray Firth and the Firth of Forth, from Kinnaird's Head to Fife Ness, and the southern section between the Thames and the coast of Sussex, from the North Foreland to Dungeness. The most vulnerable part of the East Coast, from the Forth to the Thames, or from North Berwick to Clacton, was to be patrolled by the Naval Air Service. But these arrangements were soon altered. Not many days after the outbreak of war the Germans established themselves in Belgium, and it was believed that they would use Belgium as a base for formidable attacks by aircraft on the Thames estuary and London. The forces of the Naval Air Service were therefore concentrated between the Humber and the Thames, from Immingham to Clacton. The Wash was thought to be the most likely landfall for a German airship raiding London. Regular patrols of the coast were carried out in the early days of the war, to report the movements of all enemy ships and aircraft and to detect enemy submarines. But there was not much to report, and it was weary work waiting for the enemy to begin.
The British Expeditionary Force was ready for service abroad, and it fell to the Naval Air Service to watch over its passage across the Channel. A regular patrol between Westgate, close to the North Foreland, and Ostend was maintained by seaplanes, following one another at intervals of two hours. On the 13th of August a temporary seaplane base was established at Ostend under the command of Flight Lieutenant E. T. R. Chambers, but on the 22nd of August, when the expeditionary force was safely landed and the occupation of Ostend by the Germans seemed imminent, the base was withdrawn, and the men and stores were taken back to England. An airship patrol of the Channel undertaken by airships Nos. 3 and 4 (that is to say, by the Astra-Torres and Parseval) began on the 10th of August, and was continued throughout the month. The average time of flight of a seaplane on patrol was about three hours, of an airship about twelve hours, so that the airship, which could slacken its speed and hover, had the advantage in observation. The chart printed on p. 363 illustrates the patrols carried out by the two airships on the 13th of August 1914. Here are copies of their logs for the day:
| 'Log of No. 4 Airship, 13th August 1914. | |
| 7.40 a.m. | Left Kingsnorth. |
| 9.28 | Passed Coastguard Station, shaped course for Calais. |
| 10.35 | Shaped course for Dover. |
| 11.25 | Shaped course for Calais. |
| 11.35[5] | Broke one blade of port propeller, rendering it necessary to change two for new blades. |
| 12.55 p.m. | Proceeded to Calais. |
| 1.40 | Shaped course for Dover. |
| 2.12 | Course as requisite to arrive at Calais. |
| 2.52 | " " " " " " Dover. |
| 3.20 | " " " " " " Calais. |
| 4.00 | " " " " " " Dover. |
| 4.45 | " " " " " " Calais. |
| 5.45 | " " " " " " Deal. |
| 7.30 | Arrived at Kingsnorth. |
| 7.53 | Landed. |
AIRSHIP PATROL. 13th AUGUST, 1914.
It will be seen that the Parseval, which could not fly for a whole day without landing for the replenishment of fuel, plied continually between Dover and Calais, while the Astra-Torres, which was the stronger ship, laid her course far to the east and north-east to search the Channel for the approach of hostile craft.
Once the expeditionary force was safely across the Channel, these routine patrols were discontinued, though both airships and seaplanes continued to make special scouting flights over the North Sea and Channel. The main work of the Royal Naval Air Service continued to be coastguard work. At dawn and at sunset patrols were carried out every possible day, scouting the line of the coast. The group which had its centre at the Isle of Grain was entrusted with the defence of the Thames estuary. They had to report the approach of hostile ships and aircraft, to help our submarines in attack, and to warn friendly craft. They had two sub-stations, at Clacton and Westgate, facing each other across the estuary. The monotony of the life was relieved at times by alarms. In September a seaplane on patrol from Felixstowe sighted a Zeppelin. The news was received with enthusiasm, which was damped a little when it was learned that the pilot was some way out to sea, and that his estimate of his distance from the Zeppelin was sixty miles. On the 17th of November the Admiralty suspected an impending raid by German warships, and ordered that all available aeroplanes and seaplanes should be in the air for the daylight patrol of Thursday, the 19th of November. But even war, as the philosopher remarked, has its seamy side, and the enemy did not appear.
This patrol work was tedious and, when the winter came, even dangerous; a few pilots were lost and some spent hours adrift on wrecked seaplanes. Here is the report of a December experience of Squadron Commander J. W. Seddon, over the North Sea: