The <surfaceintervalbeforedive> statement puts into brackets subsequent elements concerning the description of what happened during the surface interval before the dive (for example travelling to the new dive spot over a mountain pass, and/or through a valley with altitude and time information).
Therefore, <surfaceintervalbeforedive> is used to describe the diver's "previous history" in case his/her tissues are not "saturated" according to ambient pressure at the beginning of a dive, but this knowledge is necessary for a correct decompression calculation.
Important occurences after the dive are given inside <surfaceintervalafterdive> (for example a hyperbaric chamber treatment and the transport to this facility).
<exposuretoaltitude>, <infinity/>, <passedtime>, <wayaltitude>
<dive>, <profile>, <surfaceintervalafterdive>, <table>
(see also <dive>)
<dive id="dive-007">
<!-- at first data concerning the dive's prehistory -->
<informationbeforedive>
<surfaceintervalbeforedive>
<!-- in this case only the surface interval of 4h53min is given in seconds -->
<passedtime>17580.0</passedtime>
</surfaceintervalbeforedive>
<datetime>...</datetime>
</informationbeforedive>
<!-- now the further description of the dive is following -->
</dive>
<dive id="dive_1">
<!-- 1. dive -->
<informationbeforedive>
<!-- at first data concerning the dive's prehistory -->
<surfaceintervalbeforedive>
<infinity/>
</surfaceintervalbeforedive>
<datetime>...</datetime>
</informationbeforedive>
<!-- here more data describing the dive (profile) -->
</dive>
<dive id="dive_2">
<!-- 2. dive at same spot, 1.5 h later -->
<informationbeforedive>
<surfaceintervalbeforedive>
<passedtime>5400.0</passedtime>
</surfaceintervalbeforedive>
<datetime>...</datetime>
</informationbeforedive>
<!-- here more data describing the dive (profile) -->
</dive>
<dive id="dive_3">
<!-- 3. dive -->
<informationbeforedive>
<surfaceintervalbeforedive>
<!-- until 1 h after end of dive prolonged staying at place -->
<passedtime>3600.0</passedtime>
<!-- now going by car to the next lake -->
<!-- after 10 min of driving the valley is reached -->
<wayaltitude waytime="4200.0">500.0</wayaltitude>
<!-- 5 min driving in the valley -->
<wayaltitude waytime="4500.0">500.0</wayaltitude>
<!-- 30 min later a pass is reached -->
<wayaltitude waytime="6300.0">1250.0</wayaltitude>
<!-- 5 min enjoying the viewpoint ... -->
<wayaltitude waytime="6600.0">1250.0</wayaltitude>
<!-- 40 min driving down to the valley -->
<wayaltitude waytime="9000.0">380.0</wayaltitude>
<!-- after 20 min the next dive spot at 430.0 m is reached -->
<wayaltitude waytime="10200.0">430.0</wayaltitude>
<!-- 30 min preparations until beginning the next dive -->
<wayaltitude waytime="12000.0">430.0</wayaltitude>
</surfaceintervalbeforedive>
<datetime>...</datetime>
</informationbeforedive>
<!-- here more data describing the dive (profile) -->
</dive>