The term 'Marine Leader' can be summarized by two crossword solutions: ULTRA (5 letters) and AQUA (4 letters). ULTRA is an adjective meaning 'extreme or utmost, ' while AQUA is a Latin word for 'WATER.' Marine Leader is a term used to describe a person who is in charge of a marine environment, such as a body of WATER or ocean. This person is responsible for the safety and well-being of the marine environment, as well as the people and animals that inhabit it.