Wind Speed and Sea State

The Beaufort Scale is used as a method for judging wind speeds based on sea states. Wind drives the formation of waves, so the stronger the wind, the larger the seas will be.  

The problem with this is waves take time to form, and in the beginning, the sea state will be relatively calm compared to the photos of the sea states that correspond to each Beaufort level.  


Here, we see a view of the ocean on what looks like a mildly choppy day. There are scattered whitecaps and bits of spray flying through the air. The winds were sustained at 50 knots with gusts of 83 knots.  


Since the winds cropped up out of nowhere, the seas did not have time to mature into the towering walls that you would expect with these winds. 

These conditions are Force 10 and should produce waves of 29-41 feet! These waves look no taller than 6-10 feet.


Why the discrepancy? Well, a few factors can come into play here. First is duration of the wind. Second is depth of the water.  

The water in the picture is about 400 feet deep close to the shore and 4000 feet deep just a bit past the shore. Deep water allows waves to mature into their full size without breaking, as the water is deep enough to support the wave and allow it to move without interruption.  

The second is the duration of the wind. At the time of this photo, the winds had only been at this level for about an hour. To fully mature into the giants of the Beaufort scale, they would need at least a full day.  

If you find yourself out at sea in horrible conditions like these bit feel like putting off reefing down to your storm sails “because the seas don’t look all that bad”, consider how hard it would be to reef once they pick up! 

Reef before the storm hits they way you are safe and prepared for the winds and seas to come!