Lesson 1 - Why Weather Matters at Sea

Key Takeaways:

Marine vs. Land Weather:

• Marine weather changes faster and impacts your route, comfort, and safety more than land-based weather.
• Land forecasts often don’t reflect open sea conditions—especially regarding wind and swell.

4 Core Weather Elements:

• Air Pressure: High pressure usually brings stable, calm weather; low pressure means change and possible storms.
• Temperature: Drives pressure differences and local winds.
• Wind: Moves from high to low pressure and is influenced by geography.
• Humidity: Leads to cloud formation and rain; adds instability.

Beaufort Scale Summary:

• Converts wind speed into practical effects on sea state and sailing.
• Force 2–4 = ideal for cruising.
• Force 5–7 = reefing needed and heavier sea state.
• Force 8+ = preparation essential; risk increases.

Why It Matters:

• Influences sail choice, passage timing, crew safety, and anchoring.
• Helps you anticipate instead of react.
• Being weather-aware is part of being a responsible skipper.