The most common shapes are called open-ended spanner and ring spanner. The term wrench is generally used for tools that turn non-fastening devices (e.g. tap wrench and pipe wrench), or may be used for a monkey wrench - an adjustable spanner. In North American English, wrench is the standard term.
The definition of first mate is the person on a boat that is second in charge after the captain. An example of first mate is the person who gives orders while the captain is busy. first mate. first mate.
The coxswain is in charge of the shell. They are responsible for crew safety, which must be the prime concern. Along with steering, their role is to coach the crew. The cox acts as the coach's assistant, but in the absence of a coach, as is the case in a race, the cox becomes the coach. Being in the boat, the cox has a feel for what the crew need and a good view of technical errors. The cox needs to translate the coach's concerns into practical calls.