Admiral Sir Reginald Neville Custance, GCB, KCMG, CVO (20 September 1847 – 30 August 1935) was a Royal Navy officer.

Prince Louis of Battenberg, now First Sea Lord but normally subservient to Churchill's wishes, gave what historian Nicholas Lambert describes as “uncharacteristically fierce resistance” to appointing Custance, his former boss.

[10] Lord Sydenham of Combe (4 October 1916) and Custance (9 October 1916) complained in letters to The Times that Churchill's recent statements (Churchill was out of office at the time) that the German High Seas Fleet was effectively blockaded and that surplus forces should be used in offensive operations (similar to the views of naval theorist Julian Corbett) ignored the importance of seeking a decisive victory over the German Fleet.

Sturdee also complained in a private memorandum (24 Nov 1916) that Churchill's policy was “the exact reverse of what he advocated when in office and expressed in public speeches”.

Historian Christopher Bell thinks this not quite fair – Churchill had advocated risking old, near-obsolete ships in the attack on the Dardanelles but had never suggested weakening Britain's superiority over Germany in the North Sea.