1582 HYDROGRAPHIC MANUAL PaGE 44 



(6) It must not be assumed that the ship will pass at a safe distance from a danger just because- 

 the ship's position plots at what seems to be a safe distance from the charted or plotted position of a 

 shoal. Charted positions of shoals are occasionally inaccurate from having been charted from reports- 

 or inadequate data. 



(7) When approaching a possible danger at the time of relieving the watch, the offi?er-in-charge 

 of the bridge shall remain in charge until the danger has been passed, or until the relieving officer has 

 familiarized himself thoroughly with the situation and feels entirely competent to assume charge. 

 Any subordinates from the first watch whose services are deemed desirable shall likewise be retained^ 



(8) Refer also to 361. 



1582. Small-Boat Landings 



There is perhaps no one phase of seamanship so essential in hydrographic surveying 

 as competency in handling small boats and making landings on exposed coasts. Most 

 hydrographic surveys consist of operations along the coastal area where the sea meets 

 the shore, and where the greatest danger lies. The very nature of the operations re- 

 quires the use of small boats and repeated landings on the shore. An important feature 

 of the training of new members of a crew at the beginning of each field season is to 

 familiarize them with these duties and to provide every opportunity for them to acquire 

 practice. 



Officers and a crew who are experienced lifeboatmen and seamen are essential in 

 hydrographic surveying, but it must not be assumed that one who is an otherwise 

 competent seaman has the necessary knowledge and experience to make small-boat 

 landings under dangerous conditions. This is an art in itself, requiring a special knowl- 

 edge and skill only acquired by practical experience and which many seafaring men never 

 have occasion to practice. When undertaken by the inexperienced, the danger involved 

 can scarcely be overestimated. 



The subject is adequately treated, insofar as practicable in text, in many treatises 

 on seamanship, and these should be studied thoroughly and reviewed at the start of 

 each field season (see 9532). The rules published by the Royal National Lifeboat 

 Institution on the subject are very helpful. Some valuable comments on coast landings 

 are included on page 2, Alaska Coast Pilot, Part II. An almost infinite variety of 

 conditions may be encountered, and the method adopted must vary to meet them 

 successfully. This Manual can only emphasize the importance of the following in 

 connection with small-boat landings under difficult conditions: 



Use only experienced personnel. 



Conditions never appear as dangerous from seaward as they really are. 



Always use a steering oar, never a rudder. 



Keep the boat under control at all times. 



The outermost of a series of breakers is much the heaviest. 



In a strange locality, lie-to outside the breakers to study the particular conditions before attempt- 

 ing a landing. 



The one great danger, when running before a broken sea, is that of broaching-to. 



A number of heavy swells are often followed by a short and comparatively mild interval. 



Launching a boat through breakers is a more difficult and exhausting operation, though not 

 necessarily a more dangerous one, than making a landing under similar conditions. 



An entirely different technique is required on a steep rocky shore from that required on a gently 

 sloping sand beach. 



1583. Mags 



Flags shall be displayed by vessels of the Bureau as follows: The national ensign 

 at the flagstaff and the Union Jack at the jack staff in port or at anchor from 8 a. m. to 

 sunset; the national ensign at the gaff at sea during daylight when in sight of land or 

 other vessels; and the service flag at the fore truck when the national ensign is displayed. 

 The commission pennant shall be flown at the main truck at all times. 



