Page x contents 



Page 



96. Tables 872 



961. Velocity of sound. 962. Standard widths of line. 963. Miscellaneous conver- 

 sion tables. 964. Trigonometric functions for circle-sheet construction. 965. Three- 

 letter station names. 



97. Symbols and abbreviations for nautical charts 888 



ILLUSTRATIONS 



Figure 1. Coast and Geodetic Survey ship Explorer Frontispiece 



2. Typical layout of hydrographic survey sheets 24 



3. Organization chart of a survey ship 30 



4. Construction of predicted tide curve 37 



5. Additional lines observed with repeating theodolite 72 



6. Record of horizontal angles (direction theodolite) 73 



7. Record of horizontal angles (repeating theodolite) 73 



8. Location by range and one observed angle 84 



9. EstaVjlishing shore control by the ship-intersection method 85 



10. Establishing shore control by the buoy-intersection method 86 



11. Where offset traverse can be used advantageously along the shore 87 



12. The offset traverse method 87 



13. Sextometer rod 97 



14. Displacements on air photograph due to relief 99 



15. Radial displacement of elevated objects on air photograph 99 



16. Method of adjusted distances 102 



17. Paper-strip method 102 



18. Sextant location of stations along a precipitous shore 107 



19. Buoy location from ship stations in range with shore stations 114 



20. Buoy location by cuts from ship stations 115_ 



21. Buoy location by one angle at buoy and one cut from a ship station 116 



22. Buoy location by an angle at buoy and a direction from a shore station 118 



23. Buoy location from one angle at the buoy and an azimuth to a shore station 119 



24. Buoy location by sun azimuths to shore stations 119 



25. Buoy location by taut-wire distances 121 



26. R.A.R. station located by subaqueous distances from three-point fix positions 124 



27. Buoy station located with reference to submarine relief 126 



28. Alongshore buoys located by three-point fixes at buoys 132 



29. Offshore buoys located by cuts from three-point fix positions nearer shore 133 



30. Buoy positions strengthened by interbuoy observations 134 



31. Line of buoys located by simultaneous sextant angles 135 



32. Buoys located by sextant triangulation (single triangles) 136 



33. Buoys located by sextant triangulation (quadrilaterals) 137 



34. Line of buoys parallel to the coast 138 



35. Buoy control for three-point fixes 139 



36. Buoys located by traverse with additional shore connections 140 



37. Taut-wire sun-azimuth traverse to extend geodetic datum 141 



38. Buoy control for an isolated offshore shoal 142 



39. R.A.R. stations located by three-point fixes and acoustic distances 142 



40. Sono-radio buoys located by traverse and acoustic distances 143 



41. Sono-radio buoys located by acoustic distances 145 



42. R.A.R. shore station (general arrangement) 148 



43. Tripod signals 156 



44. Water signals 159 



45. One-barrel survey buoy 167 



46. Two-barrel survey buoys (three arrangements) 169 



47. Arrangements of buoy anchor cables 175 



