🔍 Key Concepts

• Purpose of Pilot Charts – what type of planning decisions they are mainly designed to support • Typical Pilot Chart data: winds, currents, ice, pressure, wave statistics, fog/visibility • Difference between climatology of visibility/sea state and detailed meteorological data like rain and storms

💭 Think About

• Ask yourself: When a navigator uses a Pilot Chart for route planning across an ocean, which of these four items would be least critical for choosing an economical and safe route? • Think about which items are expressed as long‑term percentages or averages on charts (climatology), and which items are usually obtained from weather forecasts and synoptic charts instead. • Which of these seems more like a detailed, local weather‑forecast parameter rather than a broad, long‑term average used for strategic passage planning?

✅ Before You Answer

• Review what symbols and tables are typically shown on North Atlantic/North Pacific Pilot Charts (wind roses, currents, gale frequency, fog, sea and swell). • Identify which choices naturally fit a percentage or frequency format (how often an event occurs in a given month). • Verify which element is usually obtained from other meteorological products rather than printed as a standard feature on pilot charts.