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Nautical Know How
  • Our Courses

      All our courses are engaging, interactive and fun! Whether formal training or simply looking to brush up, we take online learning to the next level.

    • Sailing EssentialsFreeA free course great for anyone who spends time on the water.
    • Essential Navigation & SeamanshipA great introduction to navigation and basic seamanship.
    • Day Skipper TheoryMany of the best skippers started their journey here.
    • Coastal Skipper / Yachtmaster® TheoryComing SoonEssential preparation for the Yachtmaster® practical exam.
    • SRC (VHF) Marine Radio CourseAn essential course for anyone intending to use a marine radio.
  • Directory

      Are you looking for something nautical related? Our directory is an extensive list of courses and places associated with the marine industry. Hop over and search now.

    • Places
      Find anywhere nauctical, including marinas u0026 training centres. If it exists, we’ve got it listed!
    • Courses
      We help you navigate through the complex world of training and help find what’s best for you.
  • Know-How

      We believe every day’s a school day on a boat! That’s why we built Nautical Know-How, dedicated to answering your questions. Even better, if it can’t answer your question immediately, you can request it, and we’ll add it to our knowledge base.

    • Nautical Terms & Terminology
      Understanding the language of the marine world is like trying to learn a pirate’s secret code while juggling fish. Let us explain why a sheet isn’t for your bed, why “heave ho” doesn’t mean throw up (most of the time), and why “dead reckoning” is surprisingly less ominous than it sounds.
    • Why do we have tides?
      Have you ever wondered what causes the tides? Check out this video, which introduces the forces that create the tides we experience on Earth.
    • What causes our weather?
      A video introducing the drivers behind our weather, part of our RYA Day Skipper u0026 RYA Coastal Skipper / Yachtmaster® Offshore theory courses.
    • Buoyage Flashcards
      Flashcards designed to help remember the buoys in the IALA system. If you want to learn them in detail, our module ‘Getting in and out of harbour‘, covers the IALA system and different buoys used.
    • Interactive Rule Book (COLREGs / IRPCS)
      Whether you’re a novice sailor or a seasoned skipper, we can help you navigate the IRPCS confidently and clearly. Our easy-to-use, easy-to-understand, plain English rule book with helpful interpretations of what each rule means.
    • The Salty Sea Blog
      From salty old sea dogs to fresh-faced deckhands, this blog is for anyone who finds peace, adventure, and a bit of mischief on the water. So hoist the main, set your course, and let’s sail into the stories, lessons, and musings that make life on the sea so irresistible.
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Nautical Know How
  • Our Courses

      All our courses are engaging, interactive and fun! Whether formal training or simply looking to brush up, we take online learning to the next level.

    • Sailing EssentialsFreeA free course great for anyone who spends time on the water.
    • Essential Navigation & SeamanshipA great introduction to navigation and basic seamanship.
    • Day Skipper TheoryMany of the best skippers started their journey here.
    • Coastal Skipper / Yachtmaster® TheoryComing SoonEssential preparation for the Yachtmaster® practical exam.
    • SRC (VHF) Marine Radio CourseAn essential course for anyone intending to use a marine radio.
  • Directory

      Are you looking for something nautical related? Our directory is an extensive list of courses and places associated with the marine industry. Hop over and search now.

    • Places
      Find anywhere nauctical, including marinas u0026 training centres. If it exists, we’ve got it listed!
    • Courses
      We help you navigate through the complex world of training and help find what’s best for you.
  • Know-How

      We believe every day’s a school day on a boat! That’s why we built Nautical Know-How, dedicated to answering your questions. Even better, if it can’t answer your question immediately, you can request it, and we’ll add it to our knowledge base.

    • Nautical Terms & Terminology
      Understanding the language of the marine world is like trying to learn a pirate’s secret code while juggling fish. Let us explain why a sheet isn’t for your bed, why “heave ho” doesn’t mean throw up (most of the time), and why “dead reckoning” is surprisingly less ominous than it sounds.
    • Why do we have tides?
      Have you ever wondered what causes the tides? Check out this video, which introduces the forces that create the tides we experience on Earth.
    • What causes our weather?
      A video introducing the drivers behind our weather, part of our RYA Day Skipper u0026 RYA Coastal Skipper / Yachtmaster® Offshore theory courses.
    • Buoyage Flashcards
      Flashcards designed to help remember the buoys in the IALA system. If you want to learn them in detail, our module ‘Getting in and out of harbour‘, covers the IALA system and different buoys used.
    • Interactive Rule Book (COLREGs / IRPCS)
      Whether you’re a novice sailor or a seasoned skipper, we can help you navigate the IRPCS confidently and clearly. Our easy-to-use, easy-to-understand, plain English rule book with helpful interpretations of what each rule means.
    • The Salty Sea Blog
      From salty old sea dogs to fresh-faced deckhands, this blog is for anyone who finds peace, adventure, and a bit of mischief on the water. So hoist the main, set your course, and let’s sail into the stories, lessons, and musings that make life on the sea so irresistible.
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Sign In Join now—it’s Free

Glossary

AJAX progress indicator
Nautical chart abbreviations are like the secret code of the seas—except instead of buried treasure, they lead to rocks, buoys, and mysterious dashed lines that scream, 'Don’t sail here.' Learning them can feel like cracking a pirate’s encrypted diary, but don’t worry, matey! With clever tools, quirky mnemonics, and a splash of humour, we’ll help you go from 'What’s "FOUL" mean? to confidently navigating the “Wk” wrecks and “Fl G” flashes like a salty sea captain. Think of it as Rosetta Stone, but for avoiding sandbanks!
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Results: 1071
  • Term
    Definition
  • General Nautical Terminology, Navigation Tide Tables

    Charts or listings that provide the predicted times and heights of high and low tides for specific coastal locations over a given period.

    Tide...

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  • General Nautical Terminology TillerA lever attached to the rudder head by which the helmsman moves the rudder
  • General Nautical Terminology, Navigation Time Dilution of Precision (TDOP)

    A measure used in satellite navigation systems, such as GPS, to quantify the effect of errors in the timing of satellite signals on the accuracy...

    More Details
  • General Nautical Terminology, Navigation Time to Closest Point of Approach (TCPA)

    A measure used primarily in maritime and aviation contexts to estimate the time until two moving objects (e.g., ships or aircraft) reach their...

    More Details
  • General Nautical Terminology, Navigation Time to Go (TTG)Estimated time remaining to a waypoint giving an indication of arrival time
  • General Nautical Terminology, Navigation Time Zone (TZ)

    A time zone is a region of the Earth where the same standard time is used.

    A time zone is a geographical area that observes a uniform standard...

    More Details
  • Flag Semaphore, Signals & Communication Letter T (Flag Semaphore)
    Flag semaphore indicating the letter T.

    Flag semaphore indicating the letter T.

  • Morse Code, Signals & Communication Letter T (Morse Code)

    International Morse Code sequence representing the letter T.

  • General Nautical Terminology Toe Rail

    A low, raised edge running along the outer perimeter of a boat's deck, designed to provide footing stability and prevent gear or crew from...

    More Details
  • General Nautical Terminology Topping Lift

    A line or wire used to support the boom of a sailboat when the sail is not hoisted, or to adjust the height of a spinnaker pole. 

    A topping...

    More Details
  • General Nautical Terminology Topsides

    The outer hull of a vessel above the waterline, extending from the deck to the water's edge.

    The term "topsides" is a fundamental concept in...

    More Details
  • General Nautical Terminology, Navigation Traffic Separation Scheme (TSS)

    A navigation system designed to organise the flow of vessel traffic in congested or high-risk areas, ensuring safe passage by separating opposing...

    More Details
  • General Nautical Terminology, Navigation TransitTwo fixed objects are in transit when they are in line 
  • General Nautical Terminology Transom

    The transom is the flat, vertical surface at the back of a boat. It is typically where the outboard motor or stern drive is attached to a motor...

    More Details
  • General Nautical Terminology TravellerSiding mechanism to adjust the aft end of the boom.
  • General Nautical Terminology Tri-colour LightMasthead light combining red, green and white lights in one unit.
  • General Nautical Terminology Trim

    Trim is the adjustment of a boat's sails, weight distribution, and angle relative to the water to optimise performance, balance, and...

    More Details
  • General Nautical Terminology TrimaranA vessel with three hulls
  • General Nautical Terminology Trim TabsFlaps which can be pushed up or down to adjust the angles of the bow and heel on a motor vessel
  • Organisation Trinity House

    Trinity House is a maritime organisation responsible for maintaining navigational aids, including lighthouses and buoys, along England, Wales,...

    More Details
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