Cascadia Research Collective, 218 1/2 W. 4th Avenue, Olympia, WA 98501, USAOver the last few years, studies of top predators inmarine ecosystems have benefited from the use of bio-logging systems (Naito 2004; Rutz and Hays 2009). Forexample, researchers use these techniques to study ani-mal foraging tactics and diving physiology by analyzingacceleration (body angle and stroke), and parameterssuch as swim depth and swim speeds (e.g., Sato et al.2003, 2007; Sakamoto et al. 2009).Short-finned pilot whale (Globicephala macrorhynchus),a top predator, is found worldwide in tropical and warmtemperate waters. Mature males are from 4.5 to 7 m inlength and mature females are from 3.5 to 5 m in length(Bernard and Reilly 1999). Previous studies suggestedthey are foraging during deep dives which cannot beobserved visually. Their primary prey are squid and inHawai‘i they are known to make deep dives (600–800 m)during the day, but also spend considerable periods oftime shallow diving or surface resting during the day(Baird et al. 2003). Amano and Baird (1998) recordeddeep dives over 100 m off Japan. Soto et al. (2008)recorded sound, depth, and orientation from triaxialaccelerometers and magnetometers, and suggested preychasing behavior by analyzing vertical speed and soundemission during deep dives. For a better understandingof foraging tactics and diving physiology of this species,for example studying prey pursuit in a horizontal direc-tion, stroking patterns and body angle, or assessingbehavior by acceleration, we need to record accelerationand swim speed simultaneously. However, swim speedfor short-finned pilot whales has not yet been recorded.We used remotely deployed suction-cup tags formeasuring swim speed and acceleration of short-finnedpilot whales. The understanding of toothed whale be-havior has been advanced by using suction-cup attacheddata loggers (for a review see Hooker and Baird 2001).There are several types of suction-cup attached tag: oneattached with multiple suction-cups that fixed a datalogger in place (e.g., Soto et al. 2008), which with asingle suction-cup connected to a data logger with aflexible plastic tube (Baird et al. 2005), and one with asingle suction-cup that fixed a data logger in place.With removely-deployed tags, it is difficult to set thetag parallel to the water flow. Therefore it would behard to record swim speed using a propeller with amultiple suction-cup tag. A tag using a flexible plastictube cannot record acceleration caused by the animalprecisely because it is not fixed on the animal’s body.A tag fixed on a suction-cup has been demonstratedto record swim speed and acceleration simultaneouslyin previous studies (finless porpoises, Neophocaenaphocaenoides, Akamatsu et al. 2005; sperm whales,Physeter macrocephalus, Aoki 2008). The purpose ofour work was to determine whether this type of suction-cup tag is appropriate for studying swim speed andacceleration in short-finned pilot whales, and whetherit was possible to determine behavior types based onthe data collected.