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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 & SeamanshipRYA course for beginners. Learn charts, tides, pilotage, and core seamanship with simple practice tasks.
      • Day Skipper TheoryMost PopularRYA course for inshore skippers. Plan day passages using chartwork, tides, weather, and COLREGs.
      • Coastal Skipper / Yachtmaster® TheoryComing SoonRYA course for advanced navigation and passage planning. Work with secondary ports, tidal streams, and offshore weather.
      • SRC (VHF) Marine Radio CourseRYA Short Range Certificate radio course. Study online, then take the practical exam with an RYA assessor.
  • 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 nautical, including marinas & 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 & 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 & SeamanshipRYA course for beginners. Learn charts, tides, pilotage, and core seamanship with simple practice tasks.
      • Day Skipper TheoryMost PopularRYA course for inshore skippers. Plan day passages using chartwork, tides, weather, and COLREGs.
      • Coastal Skipper / Yachtmaster® TheoryComing SoonRYA course for advanced navigation and passage planning. Work with secondary ports, tidal streams, and offshore weather.
      • SRC (VHF) Marine Radio CourseRYA Short Range Certificate radio course. Study online, then take the practical exam with an RYA assessor.
  • 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 nautical, including marinas & 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 & 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.
  • Chandlery
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: 1149
  • Term
    Definition
  • General Nautical Terminology, Signals & Communication AM

    A method of transmitting information by varying the strength (amplitude) of a carrier wave in proportion to the signal being sent.

    Amplitude...

    More Details
  • Organisation American Sailing Association (ASA)

    A US-based organisation that provides sailing education, certification, and accreditation for sailing schools and instructors. 

    The American...

    More Details
  • General Nautical Terminology Amidships

    The central part of a vessel, both longitudinally and laterally, located between the bow and stern.

    Amidships is a crucial term in nautical...

    More Details
  • General Nautical Terminology, Signals & Communication Ampitude Modulation (AM)

    A method of transmitting information by varying the strength (amplitude) of a carrier wave in proportion to the signal being sent.

    Amplitude...

    More Details
  • General Nautical Terminology Anchor

    A heavy object, typically made of metal, designed to grip the seabed and hold a vessel in position.

    An anchor is a crucial piece of equipment...

    More Details
  • General Nautical Terminology Anchorage

    A designated area where a vessel can be securely anchored, typically marked on nautical charts and chosen for its safe holding ground and...

    More Details
  • General Nautical Terminology Anchor Aweigh

    The moment when an anchor has been lifted off the seabed and is no longer holding the vessel in place.

    The term "anchor aweigh" is a...

    More Details
  • General Nautical Terminology Anchor Ball

    A black spherical day shape hoisted on a vessel to signal that it is anchored during daylight hours.

    An anchor ball is a crucial piece of...

    More Details
  • General Nautical Terminology Anchor Buoy

    A small floating marker attached to an anchor to indicate its location on the seabed.

    An anchor buoy is a vital piece of equipment used in...

    More Details
  • General Nautical Terminology Anchor Cable

    A heavy-duty rope, chain, or wire used to secure a vessel to its anchor, ensuring it remains stationary in the water.

    An anchor cable is a...

    More Details
  • General Nautical Terminology Anchor Light

    A white light displayed by a vessel at anchor to indicate its position to other vessels during the night or in poor visibility conditions.

    An...

    More Details
  • General Nautical Terminology Anchor Locker

    A dedicated storage compartment, typically located in the bow of a vessel, used to store the anchor and its associated gear, such as the rode and...

    More Details
  • General Nautical Terminology Anchor Roller

    A fitting mounted on a boat's bow designed to guide, support, and secure the anchor and its rode during deployment and retrieval.

    An anchor...

    More Details
  • General Nautical Terminology, Safety Angle of Vanishing Stability (AVS)

    The maximum angle of heel at which a vessel can recover to an upright position without capsizing.

    The Angle of Vanishing Stability (AVS) is a...

    More Details
  • General Nautical Terminology AntifoulPaint applied to hull below waterline to discourage dirt and wildlife attaching and slowing your progress. Has environmental implications
  • General Nautical Terminology, Navigation APEM More Details
  • General Nautical Terminology Apparent WindThe wind we feel. If the true wind is hitting the boat on the beam or in front of the beam the apparent wind will be situated between the boat... More Details
  • General Nautical Terminology, Navigation Appraise, Plan, Execute, Monitor (APEM) More Details
  • Organisation ASA

    A US-based organisation that provides sailing education, certification, and accreditation for sailing schools and instructors. 

    The American...

    More Details
  • General Nautical Terminology AshoreOn the land; or aground
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