SPECIMEN EXAMINATION FOR CHIEF MATE 



67 



Would you regard 'A " "B," "C" or 

 "D" sketched below as representing cor- 



rect placing of the iron in a Flinders 

 bar holder? Why? 



Wood: 



^^ 



Soft ^ 

 Iron: [^ 



I 



i 



A 



Where is there no induced magnetism 

 in vertical soft iron ? 



What is the effect of a change of 

 latitude on uncorrected deviation due to 

 permanent magnetism? 



Why is it desirable : 



(a) To check a compass adjust- 

 ment on opposite cardinal headings to 

 that of initial placement of correctors; 



(b) To check the quadrantal sphere 

 positions at an adjacent intercardinal 



heading from that of initial position- 

 ing; 



(c) To "halve" any errors found 

 in each instance? 



How would you correct easterly quad- 

 rantal deviation on a SW heading? 



If the westerly deviation increases on 

 westerly headings as the vessel steams 

 south, what adjustment should be made 

 in the Flinder's bar? 



How would you correct your compass 

 for westerly error due to permanent 

 magnetism? 



18. TIDES AND CURRENTS. 



What is meant by the term "vulgar 

 establishment of a port"? 



What is the diurnal range of the 

 tides? 



What causes the difference in height 

 between two successive high waters of 

 the tides? 



How would you determine the time of 

 high and low water for a locality not 

 listed in the Tide Tables? 



Define the term "lunitidal interval", 

 and state the various types of lunitidal 

 intervals that may occur. 



At Longview, on the Columbia River 

 (Lat. 46°-06' North and Long. 122°- 

 58' West) on 21 October 1958: 



(a) What is the time and velocity 

 of the maximum PM ebb current? 



(b) What is the direction and the 

 average velocity of the ebb current at 

 this point? 



(c) Under what conditions would 

 tabulated data of the Current Tables 

 be inapplicable to this position? 



At Newburg, New York (Lat. 41°- 



30' North and Long. 74°-00' West) on 

 29 July 1958 ; 



(a) What is the time and velocity 

 of maximum PM ebb current? 



(b) What is the average velocity 

 of the ebb at this point? 



(c) In what period of the year 

 might you expect values other than 

 those tabulated in the Hudson River? 



At the Columbia River Entrance (N. 

 Jetty) on 4 February 1958: 



(a) What is the time and height 

 of PM low water? 



(b) What is the mean range of 

 tides for this locality? 



(c) What is the diurnal range of 

 tides for this locality? 



(d) What is the range of PM tides 

 at this locality? 



At Godthaab, Greenland on 4 July 

 1958: 



(a) What is the time and height of 

 AM low water? 



(b) What is the range of AM tides 

 for this date at this locality? 



