HAYES— U. S. NAVY MV TYPE OF HYDROPHONE. 397 



tip of the cape was detected at position (6). The course around the 

 cape was then easily followed until the submarine bell on the Polluck 

 Rip Slue lightship was picked up at position (7), range 4 miles, and 

 contact made with it. 



Darkness had now fallen and with it an extremely heavy fog, so 

 thick that the bow of the submarine could hardly be seen from the 

 conning tower. It would, without doubt, have been possible to 

 navigate the vessel through Nantucket and Vineyard Sounds, as 

 was originally planned, with no great difficulty — as sounding and 

 lightship bells would have given sufficient aid. However, it was 

 thought that numbers of silent fishing boats might be anchored in 

 these waters, offering a risk of collision. Accordingly it was decided 

 to go out around these islands. The numerous and extensive shoals 

 to the south of Nantucket are well charted so that a course was laid 

 out beforehand with certain turning and checking points at various 

 well-defined shoals — (9), (10), (11), (12), (13), and (14). 



Taking a departure from the Slue lightship, which was the last 

 beacon to be seen during the night, this predetermined course was 

 readily followed. Hydrophone soundings proved to be thoroughly 

 reliable ; the various points indicated were located with ease, so that 

 the navigator, cruising at full speed through the fog and darkness, 

 was certain of his position at all times and proceeded with complete 

 confidence. When the last shoal, (14), was reached in the early 

 morning the hydrophone watch was interrupted and a compass 

 course was set for (15), a buoy off No Man's Land, nearly 40 miles 

 distant. About 9:00 A.M. the fog suddenly hfted; the island of 

 No Man's Land was seen on the starboard bow, and a few hundred 

 yards ahead was the buoy in question — less than a point off the 

 course. .' ■ i 



While this precise locating of the buoy after such a lengthy run 

 from the Slue lightship out around the islands was perhaps to be 

 partially attributed to the element of luck, nevertheless, all on board 

 considered that this result showed conclusively the aid to navigation 

 which a hydrophone equipment of this type is capable of furnishing, 

 due to its ability to give reliable soundings while the vessel continues 

 undelayed on her course. The trip, in spite of — or perhaps because 

 of — the bad weather, was voted a complete success. 



