On June 11th, however, the Grand Fleet went to sea for a cruise in northern waters principally for gunnery practices and battle exercises, which were carried out on a large scale. On this occasion the sea-planes working from the _Campania_ were utilised, so far as I am aware, for the first time in history in observing the movements of the squadrons, which were ordered to represent a large hostile fleet. From this beginning, there was a great development in the work of heavier-than-air craft operating with a fleet. The first step was the provision of a flying-off deck in a ship for sea-planes, as the extreme difficulty experienced by sea-planes in rising from the water, except in very fine weather, rendered the provision of a flying-off deck essential; the next was the substitution of aeroplanes for sea-planes, working from special carriers; and, finally, the provision of flying-off platforms in fighting ships themselves, first in light cruisers, afterwards in battle cruisers, and, eventually, in battleships; these successive developments were rendered possible by the progressive improvement in aircraft. In this way, naval power was given the assistance which air power could give it, both in reconnaissance and in making its gunnery more effective. The Scapa force proceeded to the westward through the Pentland Firth on the 11th. It carried out target practice at special targets towed by colliers to the north-westward of the Shetlands on the 12th, being joined by the Cromarty force (the 1st Battle Squadron and 7th Cruiser Squadron) that evening; the fleet then separated for night-firing. The Battle Cruiser Fleet, which had also left Rosyth on the 11th, carried out night-firing on the 12th, and the whole Grand Fleet practised battle exercises on the 13th, the Battle Cruiser Fleet afterwards firing at the targets which were towed by colliers, and rejoining my flag at daylight on the 14th. On that day further battle exercises were carried out. The _Campania_, with her sea-planes, again took part in these exercises, and an improvement in the scouting work of the sea-planes was noticeable. The Fleet then returned to the various bases, the Scapa force passing westward of the Orkneys. Whilst the main portion of the Grand Fleet was exercising in northern waters, the 3rd Battle Squadron and 3rd Cruiser Squadron, with one-half of the 1st Flotilla, cruised in the central portion of the North Sea. Other operations during the month included: