PRINCIPLES OF NAVAL ENGINEERING 



records were soon broken by subsequent gen- 

 erations of nuclear-powered submarines. The 

 modern nuclear-powered submarine is some- 

 times considered "the first true submarine" 

 because it is capable of staying submerged al- 

 most indefinitely. 



With the development of the modern missile 

 firing submarine— a nuclear-powered submarine 



which is capable of submerged firing of the 

 Polaris/Poseidon missile— the submarine has 

 become one of the most vital links in our 

 national defense. The modern nuclear-powered 

 missile firing submarine is a far cry from 

 David Bushnell's hand-propelled Turtle , but 

 an identical need led to the development of both 

 types of vessels: the need for better and more 

 effective fighting ships. 



14 



