Plain sailing, shipshape, and learning the ropes are all familiar English sayings, and they all derive from Britain’s busy seafaring history. You’ll find 25 sea- and ship-linked idioms here, together with their modern-day meanings. The list rounds off with the word - posh, also derived from ocean travel language.
The list could be used to enrich your own speech, as a teacher, or to present to your students for them to learn and draw from. (See my other teaching English resources, too.)