Figure 68. Frequency histogram of mean percent time submerged 



for ail 6-iiour summary periods and all 1990 PTTs 

 combined 106 



Figure 69. Frequency histogram of mean percent time submerged 



for all 6-hour summary periods for #823 107 



Figure 70. Frequency histogram of mean percent time submerged 



for all 6-hour summary periods for #825 108 



Figure 71. Frequency "histogram of mean percent time submerged 



for all 6-hour summary periods for #827 109 



Figure 72. Frequency histogram of mean percent time submerged 



for all 6-hour summary periods for #831 110 



Figure 73. Frequency histogram of mean percent time submerged 



for ail 6-hour summary periods for #833 Ill 



Figure 74. Frequency histogram of mean percent time submerged 



for all 6-hour summary periods for #839 112 



Figure 75. Frequency histogram of mean percent time submerged 



for all 6-hour summary periods for #840 113 



Figure 76. Comparison of percent time submerged during the 1990 



tracking study for PTTs #825, #827, #831, #833 and #840 115 



Figure 77. Comparison of percent time submerged during the 1990 



tracking study for PTTs #823 and #839 116 



Figure 78. Number of zero duration dives per 6-hour summary period 



versus percent time submerged (PTTs #823 and #839) 119 



Figure 79. The chronological relationship of average dive duration, 



speed and number of dives for PTT #823 120 



Figure 80. The chronological relationship of average dive duration, 



speed and number of dives for PTT #833 121 



Figure 81. The chronological relationship of average dive duration, 



speed and number of dives for PTT #839 122 



IX 



