Britain's immediate response to the outbreak of war was to send troops to defend the channels ports on the Belgian coast. On 28th August 1914 Capt Harold Ozanne was with the Chatham Battalion which landed in Ostend. But there was soon a change of plan and the Marines withdraw after only a few days.

In late August 1914 Belgian troops were also withdrawn from ports along the Belgian coast. The Admiralty wanted to deny the Germans submarine bases in Belgian ports for operations in the English Channel. On 24 August, German cavalry patrols were reported near Ostend and it was decided to land a small naval detachment to secure the town. The Admiralty planned to use the Channel ports as a base to attack German land supply routes, with the Royal Marine Brigade forming the basis of a landing force.

The Chatham, Portsmouth and Plymouth battalions were sent to Flanders. They were ordered to hold the town until Belgian troops who had retreated into France could be transferred and 4,000 Belgian troops arrived on 30 August. The rapid Allied retreat led the War Office to decide that supplies would have to be brought through ports in western France, as the existing arrangements in the Pas de Calais ports were too exposed. This would be more demanding on naval escort ships, leaving too few to support the force at Ostend. The Marines were re-embarked on 31 September and returned to their ports. https://en.wikipedia.org/wiki/63rd_(Royal_Naval)_Division