500 HYDROGRAPHICAL SURVEYING [chai>. xxi. 



Rigging and unrigging, dropping, and picking up beacons 

 should be considered to take the form of a recognised evolution. 



The particulars as to length of moorings, ground moorings, 

 distinguishing flags, etc., etc., having been settled beforehand, 

 so many are then prepared as there is deck space available for, 

 Avith one complete beacon triced up in position by the derrick 

 or fore yard, with the heel of the spar secured over the shijj's 

 side in readiness for the beacon to be dropped. Particular 

 attention should be given to the seizings securing the bamboo 

 to the upper part of the staff, also those for the flag at top and 

 bottom, and at each division of the different coloured breadths 

 of calico. 



All pins of shackles, whether fitted with screw or forelock, 

 rings of slips, etc., etc., upon which we are dependent for the 

 security of the beacon, should be weU moused with seizing wire, 

 for they will otherwise inevitably work loose with the constant 

 wave motion and the straining of the beacon in the tidal stream. 



The ship's berthing and rails, and all head gear included, 

 with bowsprit or jib-boom if so fitted, should be kept umdgged 

 and snugged down as far as is possible whilst engaged upon 

 beacon work, with the boat's forward davits turned fore and 

 aft on that side of the ship that is being used. 



It will be found a good plan to always work the beacons 

 on one side onh^ preferably the port side, leaving the starboard 

 side with the sounding gear rigged. 



Arrived at a spot for dropping a beacon, the commanding 

 officer, whilst manoeuvring the ship with due regard to the set 

 of the tidal stream, wind, etc., in such a manner that, on the 

 beacon being dropped, the ship will draw clear astern, gives the 

 necessary instructions to the forecastle and to the assistants 

 on the bridge. 



If in doubt as to the set of the tidal stream, a boat's wire 

 sounding machine wiU enable us to readfly ascertain this, for 

 we shall always require to know the depth beforehand. 



The executive officer during beacon work, whenever he can 

 be spared from the bridge, should himself direct the handling 

 operations of the beacon from the forecastle, whilst the boat- 

 swain with his party is more especially responsible for the moor- 

 ings, which are better treated as distinct from the beacon itself. 



The fact of the moorings reaching the bottom should always 



