IYT, RYA and ISSA: a marine-weather competency map

IYT, RYA and ISSA are distinct training systems, not three versions of one qualification. This comparison covers only weather topics supported by their official public pages. Topic overlap does not imply equivalent certificates, permission to skipper in a particular country or readiness for an exam.

What the public programmes establish

System	Verified weather emphasis	How to use our course
IYT	International Flotilla / Bareboat Skipper: basic weather, obtaining information and the coastal context; the public higher Yachtmaster pages identify meteorology and passage preparation. The separate Weather Master outline identifies worldwide weather, tropical cyclones and forecast services.	Chapters 1–9 for the foundations and coastal decisions; 10–12 for longer passages, the tropics and a complete brief. This is our reading pathway, not the official IYT sequence.
RYA	Day Skipper Theory includes meteorology. Coastal Skipper / Yachtmaster Offshore Theory explicitly develops obtaining and interpreting forecasts, working with weather systems and the barometer. Yachtmaster Ocean Theory adds worldwide meteorology and tropical revolving storms in an ocean-planning context.	Start with chapters 1–8 and 12, then extend into local effects, offshore weather and the tropics. The full RYA examination syllabus belongs to the current official syllabus/logbook, not this comparison.
ISSA	Public Inshore Skipper, Offshore Skipper and Master of Yacht pages describe progression from weather foundations to using weather information for planning. The availability of detailed competencies varies. A separate current detailed Ocean Master syllabus was not established, so we do not attribute specific outcomes to it.	Chapters 1–9 and 12 form a practical coastal set; 10–11 deepen the offshore and tropical context. Confirm the precise level names, requirements and limits of your document with the ISSA school.

The common core to put into practice

Identify the product, not just the app: the responsible service, forecast zone, bulletin type, warnings, issue and validity. Explain which legs the product does not cover.
Connect the synoptic picture with observations. Describe pressure systems and fronts, then check the barometer, clouds, wind direction and measurements. One sign cannot replace the whole picture.
Explain the sea, not only the wind. Distinguish mean wind and gust, wind sea and swell, height and period, tidal height and stream. Check shallow water, opposing current and an exposed approach using separate evidence.
Explain uncertainty without false precision. Compare the same valid times and variables; identify model dependence, missing data and timing errors. Do not turn agreement between two apps into a probability of safety.
Specify a review process, not a final verdict. State boat and crew limits, an alternative, the next update time and observable triggers for changing the plan. Establish a way to receive updates underway.

Where our material extends beyond brief course descriptions

Our treatment of model provenance, ensembles, timestamps, wave-direction conventions, AI limitations and a documented brief is our own editorial extension. A topic’s presence here does not establish that a school teaches it in the same depth or with the same tools. Ocean-model currents do not replace a local tidal atlas, and automated text is not an expert opinion without actual human review.

How to assess yourself before working with an instructor

Use your own scenario rather than a memorised textbook answer. Choose a short passage and two departure times; document source, zone and time for every leg. Example numbers are suitable for practice, but a working brief needs current verified data.

Ask another person to reproduce your reasoning. They should locate the products from your links, understand the units and distinguish issue and validity. If your spoken explanation is essential to do that, the brief is not yet reproducible.

Assess the explanation, not the number of ticks. A strong answer states a fact, its origin, its limitation and an action. A partial answer identifies a phenomenon but does not connect it to the passage. A weak answer relies on one display, promises safety or overlooks an unchecked warning. This is our practice rubric, not a school assessment.

Bring specific questions to the instructor: where the approach remains exposed to swell after a wind shift; when the barometer stopped matching the expected pattern; which tidal data cover a narrow channel; or how boat-speed changes move the critical valid hour. Boat handling, communications and emergency drills require separate practice.

Check the current documents, not only the brand name. Ask which course and syllabus version apply, how theory is assessed, and what practice and experience are required. Recognition depends on the jurisdiction, flag, charter arrangements and vessel use; this page does not establish it.

Official pages to verify the programme

Public-page review: 28 September 2026. This maps published coverage; it is neither a complete official syllabus nor a reproduction of textbooks. Obtain the full learning outcomes and examination requirements directly from the school.

RYA

IYT

ISSA

Choose a chapter and start practising