Summary

John Jellicoe, 1st Earl Jellicoe Memorandum to the First Lord of the Admiralty on submarine warfare…

The destroyer is, of course, very efficient defensively as a screen to individual ships, or to a large number of ships, but, except in more or less confined waters, is not an efficient offensive weapon, because she must, with her present means of offence, actually get into contact with a submarine, or very nearly into contact, which is a difficult matter if the submarine has plenty of sea room.
Source: Wikisource

John Jellicoe, 1st Earl Jellicoe Memorandum to the First Lord of the Admiralty on submarine warfare…

In the first place, submarines in this locality have so much sea room that it is impracticable to corner them by means of destroyer sweeps when they are sighted, and there is the added difficulty of bad weather for a great part of the year. Secondly, owing to the constant expectation of the fleet being required for sea at short notice, and the serious risks involved by sailing without the destroyer force as a submarine screen, it is not possible to send destroyers far from the base in any numbers or to allow them to get short of fuel.
Source: Wikisource

John Jellicoe, 1st Earl Jellicoe Memorandum to the First Lord of the Admiralty on submarine warfare…

The destroyer, although very effective in confined waters, and when present in large numbers, is ineffective for offence in open waters, as is any other vessel, by reason of the fact that the submarine has a submerged radius of action of well over one hundred miles, and can therefore, even if located, escape with great facility.
Source: Wikisource

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