# Table 1 Recommended descriptive device parameters, shown here for select tags used in recent marine mammal studies (see Table 2)

Device Volume (ml) Mass (g) Areaa (cm2) Lengthb (mm) Forcec (static, submerged) (N) Forced (dynamic) at a = 9.8 ms−2 (N) Pressuree (static) (N/mm2) Pressuref (dynamic) at a = 9.8 ms−2 (N/mm2)
LHX1 202 118 13.85 128 −0.87 1.16 6.28 8.38
LHX2 79 54 8.55 97 −0.26 0.53 3.04 6.20
VHF 119 150 13.37 90 0.27 1.47 2.02 10.99
TDR 17 35 2.3 69 0.18 0.34 7.83 14.78
Effect Body mass set point Cost of locomotion Entrapment Entrapment Cost of locomotion Cost of locomotion Tissue effects Tissue effects
1. aSmallest cross-sectional area
2. bLongest exterior dimension
3. cForce is calculated for subjects fully submerged in saltwater (density 1.025) as $$F\left( N \right) = [{\text{volume }}\left( {\text{ml}} \right) \times 1.025 - {\text{mass }}\left( {\text{g}} \right)] \times 9.8067 \, ({\text{ms}}^{ - 2} )/1000$$; a negative value indicates the device is buoyant
4. dThis corresponds to the inertial force resulting from the tag mass being exposed to an acceleration a and is calculated as F(N) = m (kg) × a (ms−2). For a = g = 9.8067 ms−2, the force is also equal to the tag weight in air at sea level
5. e,fThis is a measure of the maximum pressure the tag exerts on surrounding tissue, and is calculated as force per unit area. Static pressure is exerted by the buoyancy in a non-moving submerged animal, and dynamic pressure is resulting from dynamic acceleration of the animal and varies with a. For a = g, this equals the pressure exerted by a tag in a non-moving, non-submerged animal