This page has been archived on the Web
Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please contact us to request a format other than those available.
Secrets of the St. Lawrence
The wind in your sails - Fast or slow?
10 nautical miles off Matane
Destination: Grande-Vallée - Wind direction: Southwesterly; wind speed: 15 knots.
- "We're going to head for the shore. If my grandfather is right, the wind will pick up closer in."
When the wind is blowing parallel to the shore, it creates a narrow band in which the wind picks up speed or drops off sharply, depending on whether the shore is on your right or your left with the wind at your back.
When the shore is on your right and less than 3 nautical miles off, the convergence effect means that the wind will automatically be 25 % stronger.
The wind will shift slightly to the left because of the friction created by the shore and will join forces with the sea wind.
The effect is the opposite when the shore is on your left.
The airstream that diverges to the left because of friction on the shore will meet and slow down the sea wind.
Watch out for drainage winds. Where there is convergence, the wind over the ground will flow down a valley and, when it meets the sea, may give a nasty shock to anyone caught hugging the shore too closely.
- 1. Fore to aft
- 2. What Cartier missed out on
- 3. Conversion
- 4. The Secrets of the St Lawrence
- 5. The wind in your sails - Hard a-port!
- 6. The wind in your sails - Fast or slow?
- 7. The wind in your sails - The wind's paths
- 8. The wind in your sails - Against the wall
- 9. The wind in your sails - Solar energy
- 10. The wind in your sails - Under the stars
- 11. The wind and the waves - The windway
- 12. The wind and the waves - Wave wars
- 13. The wind and the waves - Graveyards
- 14. The wind and the waves - Conflicting seas
- 15. Symbols
- 16. The St Lawrence, from 1 to... - Legend
- 17. The St Lawrence, from 1 to... - Calling all sailors
- 18. The St Lawrence, from 1 to... Hot spots
- 19. Local listings - Québec - Pointe-des-Monts
- 20. Local listings - Pointe-des-Monts - Cap Whittle
- 21. Local listings - Cap Whittle - Blanc-Sablon
- 22. Local listings - Gaspésie - Baie des Chaleurs
- 23. Local listings - Îles de la Madeleine
- 24. Sailors take warning - White-outs
- 25. Sailors take warning - The sky above us
- 26. Sailors take warning - Keeping a weather eye
- 27. Sailors take warning - Fair weather and foul
- 28. Sailors take warning - The unexpected
- 29. The four seasons - Wind aplenty
- 30. The four seasons - Vessel icing
- 31. The four seasons - Ice cycle
- 32. Extra - Beaufort
- 33. Extra - Handy references
- 34. Extra - Old Salts and Sea-dogs
- 35. Extra - The crew
- 36. Extra - A to Z
- 37. Extra - Stations
- 38. Extra - Areas
- 39. Credits
- Date modified: