Northern Fulmars are relatively lightweight, aerial seabirds, and are not anatomically well-adapted for diving or underwater swimming. However, Fisher (1952) stated, "the literature is full of controversy about the diving of fulmars." He listed eight observers reporting diving; presumably, their reports represented most of the detailed descriptions of this behavior discovered during an extensive literature search conducted on the species (see Fisher 1952). Subsequent published reports are few, if any. Descriptions in more recent references (e.g., Palmer 1962; Cramp 1977) apparently are derived from Fisher's synthesis.