Indefatigable and Dominion sea power

Australia and New Zealand were intended as flagships for Dominion cruising squadrons, with South Africa and Canada also invited into the scheme. A ten-knot cruising speed suited contemporary merchant traffic, while a quoted maximum of 25.8 knots was adequate against most cruisers they were expected to encounter. Heavy guns suited attacks on weaker cruisers and merchant ships, while limited protection made combat with comparable capital ships dangerous. Their displacement and cost offered Britain a practical basis for building substantial numbers of trade-protection ships. Canadian opposition included the argument that such a vessel would provoke the United States. The counterargument was that American knowledge of the ship's capabilities gave little reason for alarm.