BML Revision: Meteorology (Section 2)

Revision card 6 of 16 — Boatmaster's Licence, Tier 1 Level 2 Underpinning Knowledge, MSN 1853 Annex 10. Extended over Annex 9 — same foundation, plus three new items reflecting coastal exposure to open weather.

Carried Over From Level 1

• The weather services available to shipping
• Meteorological terms in enough depth to actually interpret conditions, not just recite definitions
• Types of cloud, cloud cover and precipitation
• Visibility, including horizontal visibility — define it precisely
• How to make non-instrumental observations (reading the sky and sea state without instruments)
• How to recognise and respond to an extreme weather forecast or rapidly emerging conditions

New for Level 2

• Wind force, the Beaufort scale, wind direction, and the difference between true and apparent wind
• Waves, sea state and swell state
• Identify the main synoptic patterns on surface charts and describe the associated weather (a UK-specific requirement)

Quick Self-Check

• Can you define horizontal visibility without checking a book?
• What's the difference between true wind and apparent wind, and why does it matter under way?
• What does a given Beaufort force actually look like at sea, not just on a chart?

Related Reading

• Spirit of Discovery — a Force 10 Bay of Biscay crossing where weather routing advice existed but wasn't formally challenged before the passage plan was agreed