CONTENTS 



I'ayc 



1. General Requirements 1 



2. Plans and Preparations 21 



3. Equipment and Instruments 42 



4. Control and Signal Building.. _ — . 112 



5. Hydrography - 126 



6. The Smooth Sheet 200 



7. Reports and Miscellaneous .— 241 



Index - 267 



TABLES 



Table Pnge 



1. Projection line intervals for various scales 4 



2. Units for recorded soundings and reducers -.— _ .— 14 



3. Standard depth curves — — . 15 



4. Supplemental depth curves — 15 



5. Scale equivalents for laying out survey sheets 27 



6. Three-letter station names. _ 124 



7. Conversion table — microseconds to meters -.. - 131 



8. Conversion table — Sjtatute miles to meters .., . 132 



9. Distance circle intervals and units - - 133 



10. Sediments classified by size - - 160 



11. Example of velocity correction computation 183 



12. Conversion of reduced soundings . 193 



13. ^Schedule of penciled and inked details - 204 



14. Velocity of sound in sea water 256 



15. Salinity corrections (to be applied to Table 14) - 256 



16. Pressure corrections (to be applied to Table 14) . ... 258 



17. Velocity correction factors - 259 



18. Natural half-cosecants and half-cotangents _ . 264 



19. Linear distance conversion — fathoms — meters — 



feet — yards 265 



20. Linear distance conversion — nautical miles — statute 



miles — kilometers . 266 



21. Temperature conversion . 266 



ILLUSTRATIONS 



Figure I'oyc 



1. Coast and Geodetic Survey Ship SURVEYOR II 



2. Layout of hydrographic sheets _ 3 



3. Symbols for progress sketches .._. 36 



4. Construction of predicted tide curve 40 



5. Drafting room of a survey ship 42 



6. Hydrographic survey launch . ._ 43 



7. Hydrographic sextant with endless tangent screw 46 



8. Graph for corrections to inclined sextant angles 49 



9. Three-arm metal protractor 50 



10. Three-arm plastic protractors 52 



11. Construction of plate for testing protractors 53 



(Change 1) VH 



