44 



HYDROGRAPHIC MANUAL 



One of the ship's launches is usually de- 

 signed as a work boat for transferring per- 

 sonnel, equipment, and supplies between the 

 ship and the beach. This will include lum- 

 ber, camp gear, or equipment for electronic 

 stations. A small landing craft is most suit- 

 able for this purpose. The boat may be used 

 by signal building, triangulation, or photo- 

 grammetric parties. 



The launches should be strongly built to 

 withstand daily use and severe strains to 

 which they are subjected by frequent lower- 

 ing and hoisting under adverse conditions of 

 sea and swell and the occasional groundings 

 which are unavoidable on inshore hydrog- 

 raphy. Each launch should be equipped with 

 lifeboat gear, a portable echo sounder, and a 

 radiotelephone (see 2-26). 



3-3 Small boats. — Each ship will carry 

 one or two powered whaleboats which are 

 combined lifeboats and work boats. They are 

 very useful for supplying camp parties, tend- 

 ing tide gages, and similar operations where 

 launches are not required. The ship will also 

 carry a number of skiffs or dories as may 

 be required by the nature of the assigned 

 project. In shoal water bays and sounds 

 along the Atlantic and Gulf Coasts hydro- 

 graphic surveys are frequently conducted 

 with specially designed skiffs powered by out- 

 board motors. The Chesapeake Bay skiff is 

 typical of this class of boat. 



3-4 Navigation equipment. — Every sur- 

 vey vessel, regardless of size, must be prop- 

 erly equipped with modern instruments for 

 safe navigation. These include compasses, 

 chronometers, sextants, charts. Coast Pilots, 

 Light Lists, etc. The larger vessels will be 

 equipped with Standard Loran, radar, and 

 gyro compasses. The Commanding Officer, 

 assisted by the navigating officer, is respon- 

 sible for the care and maintenance of all 

 instruments, equipment, and supplies neces- 

 sary for safe navigation. Magnetic com- 

 passes, both standard and steering, must be 

 properly compensated and compass errors 

 known even though the ship is equipped with 

 a gyro compass system (see 2-28). Instruc- 

 tions for adjustment and compensation of 



magnetic compasses will be found in H.O. 

 Publication No. 9, Bowditch, (1958 Edition) 

 and in H.O. Publication No. 226, Handbook 

 of Magnetic Compass Adjustment and 

 Compensations. 



3-5 Care of survey instruments. — A ship 

 has two general classes of survey instru- 

 ments: (1) those permanently installed, and 

 (2) portable instruments. The first group in- 

 cludes large equipage as electric sounding 

 machines and oceanographic winches, deep 

 water echo sounders, and electronic position 

 fixing equipment. The second group includes 

 all small survey instruments and some port- 

 able equipment such as shoal water echo 

 sounders and current buoys and meters. 



The Chief of Party, navigating officer, or 

 other officer specifically assigned such duty, 

 is responsible for the proper care and main- 

 tenance of all survey instruments and equip- 

 ment. Various members of the ship's comple- 

 ment may be required to service and maintain 

 these instruments. The electronics or radio 

 department is charged with the care of all 

 echo sounders, electronic position fixing 

 equipment including radar and Loran, all 

 radio equipment, and may be responsible for 

 servicing the gyro compass. A service man- 

 ual is provided with each equipment. Sub- 

 sequent discussion will refer only to the use 

 of these instruments and precautions to be 

 observed. 



The Engineer Department shall service 

 and maintain the deck machinery including 

 all hoists and winches. The Chief Quarter- 

 master and his assistants are responsible for 

 proper care and storage of all other survey 

 instruments. 



Instruments in daily use must be carefully 

 cleaned, dried when necessary, and properly 

 stored after being returned from the field. 

 Abrasive cleaners must not be used on grad- 

 uated arcs or circles or on sextant mirrors. 

 Only approved grades of instrument oils 

 shall be used. The navigating officer should 

 supervise this work, make periodic inspec- 

 tions of instruments, test and adjust them 

 when necessary, maintain an accurate inven- 

 tory of instruments, and make any repairs 

 that can be accomplished in the field. At the 



