A midshipman is a candidate for officer aboard a navy ship. The midshipman joins usually at the age of 12 to 17 years and trains in all manners of seamanship, ship handling, navigation, and leadership. At the completion of his training, the midshipman stands before a board of captains for examination for lieutenant.
The midshipman is so named as he berths in the midshipmen's quarters amidships.
Officers berth aft, midshipman berth amidships, and the crew forward.
Once the midshipman has been trained in certain aspects of shipboard life, he may take charge of certain evolutions.
- Midshipman at Wikipedia