Crew of the submarine rescue vessel WIDGEON watch the test sub- 

 merging of the submarine APOGON. The submerging operation was 

 difficult; never before had there been occasion to submerge a sub- 

 marine without crew aboard. The method used was to fill part of the 

 ballast tanks with water, then suspend heavy weights from the bow 

 and stern by cables of carefully chosen length. These weights over- 

 came the submarine's residual buoyancy and drew her down to the 

 desired depth. She could be surfaced again by pumping air back into 



her ballast tanks. 



Plate 17 



