The Fulmar was basically a version of the P.4/34 which had been adapted for naval use. Fairey submitted their modified design as a response to Specification O.8/38, which called for a two-crew fighter capable of observation and fleet defence operations. As the prospective aircraft was not expected to encounter any major fighter opposition, as Nazi Germany, Britain's only foreseen enemy during this era, possessed no aircraft carriers of its own, factors such as long range and heavy armament were considered to be more important than a high level of either manoeuvrability or speed. As the type was intended to routinely perform lengthy flights over the ocean, the presence of a navigator / wireless operator was considered to be an essential element, especially when flying at nighttime or during poor weather conditions.