"On the night of 17 May 1942, while conducting a surface patrol off Truk during her second war patrol, Grampus was detected by a Japanese patrol vessel and forced to make a quick dive. While passing 30 foot depth, one shell, believed to have been a 3-inch or 4.7-inch common projectile, struck the starboard bulwark of the cigarette deck and detonated approximately three feet beyond its point of impact about two feet above the cigarette deck over the main engine air induction trunk. While no damage of a serious or military nature was caused, and Grampus experienced no difficulty in subsequently evading the enemy, the action has been included in this report to illustrate the shrapnel effect of medium caliber projectiles and the obvious vulnerability of submarines to such attacks. While other U.S. submarines have been more heavily damaged by gunfire attack, this experience of Grampus was chosen wince it is the only such action in which photographs of the damage were available to the Bureau. "

"On the night of 17 May 1942, while conducting a surface patrol off Truk during her second war patrol, Grampus was detected by a Japanese patrol vessel and forced to make a quick dive. While passing 30 foot depth, one shell, believed to have been a 3-inch or 4.7-inch common projectile, struck the starboard bulwark of the cigarette deck and detonated approximately three feet beyond its point of impact about two feet above the cigarette deck over the main engine air induction trunk. While no damage of a serious or military nature was caused, and Grampus experienced no difficulty in subsequently evading the enemy, the action has been included in this report to illustrate the shrapnel effect of medium caliber projectiles and the obvious vulnerability of submarines to such attacks. While other U.S. submarines have been more heavily damaged by gunfire attack, this experience of Grampus was chosen wince it is the only such action in which photographs of the damage were available to the Bureau. "

"On the night of 17 May 1942, while conducting a surface patrol off Truk during her second war patrol, Grampus was detected by a Japanese patrol vessel and forced to make a quick dive. While passing 30 foot depth, one shell, believed to have been a 3-inch or 4.7-inch common projectile, struck the starboard bulwark of the cigarette deck and detonated approximately three feet beyond its point of impact about two feet above the cigarette deck over the main engine air induction trunk. While no damage of a serious or military nature was caused, and Grampus experienced no difficulty in subsequently evading the enemy, the action has been included in this report to illustrate the shrapnel effect of medium caliber projectiles and the obvious vulnerability of submarines to such attacks. While other U.S. submarines have been more heavily damaged by gunfire attack, this experience of Grampus was chosen wince it is the only such action in which photographs of the damage were available to the Bureau. "