The Pembroke Haven Yacht Club started life as a Royal Air Force Yacht Club for the Pembroke Dock RAF Squadrons that were based there and hence it is one of the few Yacht Clubs in the world to feature on its burgee an aircraft a Sunderland who were base in the Haven during the Second World War.

SHORT SUNDERLAND - The Short S.25 Sunderland was a four-engine general-purpose flying-boat designed during 1933/34 in response to Specification R.2/33, which spelt out the needs of Operational Requirement 8 as a replacement for the biplane 'boats then in service. Designed under direction of Arthur Gouge, S.25 retained overall configuration and geometry of Scion Senior, and was in many respects the military counterpart of S.23 Empire Boat, which was the first to fly. A single prototype S.25 ordered in 1934 for competitive evaluation against Saro A. 33. Powered by four 950 hp Bristol Pegasus X engines, prototype K4774 first flew on October 16, 1937. After four flights, sweepback of 4.5 deg introduced on the main planes, and 1,010 hp Pegasus XXIIs fitted; testing in this form resumed on March 7, 1938.

Short Sunderland I: Initial production version of S.25, the first 11 being ordered to Specification 22/36 and OR.42 at the same time as 11 Saro A.31s ordered to Specification 21/36 (the latter being cancelled after A. 31 prototype damaged beyond repair on October 25, 1938). Further contracts brought total of Short Sunderland Is built to 74 by Shorts at Rochester and 15 by Blackburn at Dumbarton. First of development batch flew on April 21, 1938 and 42 Short Sunderland Is flying by September 1939; first by Blackburn flew late-1941. Short Sunderland I was powered by four 1,010 hp Pegasus XXII engines and carried a crew of 9-10. Armament comprised a single (later, two) guns in FN11 nose turret, four guns in FN13 tail turret and (later aircraft) two Vickers 'K' guns in dorsal hatches, all of 0.303-in (7.7-mm) calibre'. A 2,000 Ib (908 kg) bomb-load was carried. Service use began June 1938 with No 230 Sqn at Seletar and No 210 Sqn at Pembroke Dock, the latter unit flying the first wartime sortie - a convoy patrol - on September 3. At that time, No 228 Sqn also flying Short Sunderland's at Alexandria, Egypt, and No 204 at Mount Batten. Nine Mk Is released by RAF to equip No 10 Sqn, RAAF, still in UK when war began, becoming operational with Australian crews (but retaining RAF serials in place of A18-1 to A18-9 allocated). Two further squadrons, Nos 95 and 201, equipped from 1940.Max speed, 210 mph (338 kmlh). Rate of climb, 1,200 ft/min (6.1 mlsec). Ceiling, 20,500 ft (6,248 m). Range, 2,910 mis (4,686 km). Empty weight, 28,290 Ib (12,832 kg). Gross weight, 45,700 Ib (20,730 kg). Span, 112 ft 8 in (34.34 m). Length, 85 ft 8 in (26.11 m). Wing area, 1,487 sq ft (138.14m2).

Short Sunderland II: Operationally-improved Mk I with 815 hp Pegasus XVIII engines and two-speed superchargers, FN7 two-gun dorsal turret in place of open 'K'-gun mounts, and FN4A tail turret with double rpg. Most Mk Us also fitted with ASV Mk II radar, indicated by aerial masts and transmitter loops on rear fuselage, and central and under wing Yagi homing aerials. Prototype conversion of (first Blackburn-built) Mk I, T9083, followed by 23 by Shorts at Rochester, five by Blackburn and five by Short & Harland in Belfast (where first flew on April 24, 1942). Served alongside Mk Is in four squadrons and as initial equipment of four more.

Short Sunderland III: Principal war-time production and service version, featuring improved low-drag hull design and faired main step. Other features as Mk II. Prototype (Mk I conversion) T9042 flown at Rochester on June 28, 1941, and first production Mk III, also at Rochester, on December 15, 1941. Production totals, 186 from Rochester, 71 from Belfast, 170 from Blackburn Dumbarton and 35 from Short-operated factory on Lake Windermere in the English Lake District. The Windermere factory also did some conversion work upgrading Mark III Sunderland's to Mark Vs (thanks John Evans, Pembroke Dock, Wales).