The Blohm & Voss BV 138, nicknamed "Seedrache" (Sea Dragon), was a trimotor flying boat developed during the early 1930s. The BV 138 was Blohm & Voss' first entry into the aircraft industry, with the choice of developing a flying boat considered a natural fit for B&V, a shipbuilding company. The first prototype, fitted with a pair of Jumo 205C engines, made its first flight on 15 July 1937, during which many issues were identified, primarily the underpowered engines and lack of stability. As a result, the BV 138 was extensively redesigned, most notably with the addition of a third engine on the centreline above the wings. Once these issues were resolved, the BV 138 was accepted by the Luftwaffe for service as their main maritime patrol aircraft and would serve extensively until the end of the war. In total, 297 BV 138s of all variants were built.

The first production model of the BV 138, the A-1, was identical to the revised prototype, followed by the B-1 variant with upgraded Ju 205D engines. Further developments resulted in the BV 138 C-1, the most produced variant of the BV 138. The C-1's main difference was a four-bladed propeller fitted to the centre engine, while the wing engines received reinforced three-bladed propellers. In total, 227 of the C-1 variant were built.

Introduced in Update 2.9 "Direct Hit", the BV 138 C-1 is an extremely slow aircraft, with overall sluggish handling, which makes it quite easy for most planes to catch up with it. However, it is more than capable of holding its own thanks to its powerful defensive armaments of two 20 mm autocannons and a single 13 mm machine gun. Since the BV 138 will regularly face small-calibre machine guns, its hull can soak up huge amounts of damage. However, the BV 138's defensive guns have several glaring blind spots, especially directly above and below the aircraft. This, along with its poor agility in general, makes it vulnerable to opponents who can outmanoeuvre it.