56 
Teil C - Annex 
Figure 9: Principle of transect counting after Garthe et al. (2002). The ship is at position B, one or 
half a minute after having left position A (depending on cruising speed, and thus length of the 
snapshot area). 
Table 3: Length of snapshot areas as a function of the ship’s speed (after Garthe et al. 
2002). 
Speed 
(in knots) 
Distance covered (in m) 
in 1 min. 
in 30 s 
7 
216 
108 
8 
247 
123 
9 
278 
139 
10 
309 
154 
11 
340 
170 
12 
370 
185 
13 
401 
201 
14 
432 
216 
15 
463 
232 
16 
494 
247 
17 
525 
262 
18 
556 
278