When should one use the adjective “marine” and not “maritime” or “nautical”? This is a tricky question. All three words are connected with the sea and often applied interchangeably without people noticing the difference.
Sometimes it boils down to customary usage. Certain countries are considered “maritime powers” on account of their having formidable navies. Art critics label seascapes and other sea-related artworks as “marine art”, but the institutions that house them are always called “maritime museums”. So what’s the difference? The online etymological dictionary Etymonline defines marine as “found in or pertaining to the sea”, from the Old French marin (mid-15th century). Likewise, maritime means “of or pertaining to the sea,” from the French maritime (16th century.)
Should one say “maritime professional” or “marine professional”? One could argue that the latter is best applied to active seafarers, offshore rig workers, harbour pilots, marine surveyors, etc. On the other hand, “maritime professional” is more general and may include maritime educators with little or no sea experience.
The adjective “nautical” is much less unwieldy as it pertains in particular to ships, sailors and sailing. Thus a seaman learns how to use nautical charts as part of seamanship, and a nautical dictionary contains words related to ships, ship’s equipment and navigation.
Nautical college or maritime college? What the hells does it matter if the institution is only after collecting tuition fees?