I’ve got a new blog post available. It's called "Nautical Idioms in English, Part 2: What Do They Mean and Where Did They Come From?" Click the link below to read or listen to the audio version. https://www.difficultenglishexplained.com/blog/nautical-idioms-part-2 
The easiest way to learn and really remember idioms is to learn about their history. When you understand where they came from, it's a lot easier to remember what they mean. Featured idioms are: 1) dead in the water 2) three sheets to the wind 3) to go by the board