52 HYDROGRAPHICAL SURVEYING [chap. i. 



2 inches, may be found useful in some types of whalers, as, 

 with gear along the middle of the boat, and the low gunwale 

 of an ordinary whaler, the loom of the oar cannot be depressed 

 enough with a ser\'ice crutch, when in broken water, for the 

 blade to clear the tips of the waves. 



Lockers, built in bow and stern, are useful for keeping gear 

 and instruments in. These should be canvased over, for 

 unless built of two thicknesses of wood, which is heavy, the 

 tops will soon leak after a few months' hot sun. The top of 

 the bow locker raises the leadsman, so that he can throw his 

 lead well ahead, and he should have his foremost awning 

 stanchion sliipped, as a support in rough water. 



The awning should be cut at the after-thwart, so as to 

 enable the afterpart to be tipped, when it is necessary to 

 stand up to take angles. 



A waterproof sheet spread over a line between the two 

 awning stanchions, and covering the stern-sheets, with the 

 four corners secured outside the gunwale, forms a convenient 

 tent for the protection of the sounding-board in showery 

 weather. 



A plank secured across the stern-sheets serves to mount a 

 small ^^dre sounding machine when required. 

 Cutters Cutters should also be fitted with bow and stern lockers, 



and a table can be arranged in stern-sheets if thought 

 necessary. No other special fitting is required beyond those 

 given below for all boats. 



FITTINGS AND GEAR FOR ALL BOATS USEFUL FOR 

 GENERAL SURVEYING WORK. 



^^^^ All boats should have stout iron keel bands. With the 



constant grounding and running over rocks, inevitable in 

 surveying work, these save the boats enormously. With 

 coppered steam cutters these must be of brass, fastened outside 

 the copper sheets. 



A galvanised-iron reel, under one of the foremost thwarts, 

 to hold a 100-fathoni line. 



Sounding ^ small galvanised-iron davit, \\dtli snatch block to place 

 sounding fine in when in deep water, so that several men 



