clear bridge. The two solid arrows point towards the 

 times during which the craft cannot pass. Earliest 

 passage would be at time 1730. 



2. Boat movements in shallow streams or canals near this 

 station. 



Maximum use of shallow waterways at or near this 

 station depends upon maximum water depth available. 

 Times of these occurrences may be determined by 

 examining the monthly water-level chart and noting 

 times of extended minimum and maximum heights. 



TIME Z0NE-8(HOTEL) 

 TIME IN HOURS 



12 15 



Figure A-1. Example of Hourly Water Level Contour Chart 



364 



