At what wind speed will salt water "boil"?

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During hurricane Lenny in 1999, I was anchored on my sailboat in a protected cove in the Virgin Islands. The winds were about 60 mph with gusts to an estimated 80 mph where we were. I observed that during the gusts, the salt water would "boil", that is, totally evaporate the surface into a cloud about 6 to 8 feet thick. I wondered if that point was 74 mph, the speed classifying the wind to hurricane status. Obviously, as the wind increases, the air pressure decreases, causing the evaporation to increase. The air temperature will also change.

My question is, does the classification of "hurricane" kick in just as the visual effect of cloud formation on the surface occurs? Since the origin of the word "hurricane" is from the Caribe Indians, I wonder if when the vapor hit the fan, they said, "Look, this is a hurricane".
 

anorlunda

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The sea boiling is a metaphor. It does not mean boiling as in a tea kettle.

I think your question is best answered by the definitions and pictures of the Beaufort Wind scale.

https://www.britannica.com/science/Beaufort-scale said:
force 12-17, wind 64 knots (74 mph) and above, Hurricane, the air is filled with foam and spray; sea is completely white with driving spray; visibility very seriously affected
So I would interpret your word "cloud" as "driving spray"

Refer to your copy of Chapman's "Piloting & Seamanship" on board, it has a very good series of pictures of the sea surface as each step in the Beufort scale.

May you have fair winds and following seas.
 
Thank you for your rapid response. I think I knew that already but I just didn't put it together. Anyway, here is a photo of me at the helm during one of those wind gusts.
 

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anorlunda

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Thanks, your picture confirms what they say about hurricanes --- visibility sucks.

You were at anchor, what was your tackle? what was your scope?

I'm an ex cruiser myself, so I can relate.
 
Good morning

Well, the story leading up to Lenny is interesting. We bought Spitfire in April of 1999 in Ft Lauderdale. Our shake down cruise was a non- stop to New Bedford, MA, or so we thought. Lost steering in a near gale 90 miles off Atlantic City, NJ, and surfed in to that harbor through the breakwater in 12 foot seas. I did the repairs and completed that trip. Over that summer, we went through hurricane Floyd, waited out a second hurricane before heading south, rode the tail end of it to Bermuda, only to discover fuel issues causing me to sail through the land cut at St George's and up to the customs dock. We thought we fixed the fuel issue and left for the Virgin Islands. Four days, sixteen hours and forty minutes later, we were on our mooring on St John, our home base. During this last leg, the fuel issue got us again. We didn't have time to troubleshoot it as we went right to a boat show that was cut short by Lenny.

The issue with the fuel was that Spitfire carried 130 gallons of diesel in three tanks. Selection of which tank to pull from (and return) was through a three-way selector valve. The previous owner (Spitfire was built in 1981) only motored wherever he went and we sailed everywhere we went. The tanks were mounted athwart ship and their respective pickups where outboard. After Lenny, I had time to pull the floor boards and discover this. I had simply chosen the wrong tank for the tack. Operator error.

Anyway, we carried two 30 kg Bruce anchors that we deployed with 150 feet of 3/8 chain each and 100 feet of 1.25" line with chafe gear. We were in twenty-two feet of water. This tackle was put out to the expected direction of Lenny's wind. Wrong-way Lenny lived up to his name as the winds never switched as expected. We were sitting on a NPS mooring waiting for the switch that never came and our anchors, chain and line we not actually used. We also carried a 66 lbs CQR anchor (also not used during Lenny) as our everyday hook. The excessive ground tackle was kept in a storage locker we had on St John.

As the gusts came over the hills, I would power up in gear to take the strain off the mooring.

We lost Spitfire to hurricane Irma in 2017 while on the hard in Virgon Gorda, BVI. The eye passed directly overhead (minimum wind speed at the wall was reported ar 185 mph - I am sure there were "clouds" that day :).

We had put sailing 62,000 miles on Spitfire in the 18 years that we owned her and had 32,000 miles on Destiny, our Hinckley Bermuda 40, MK III yawl when we owned for 10 years prior.

The three happiest days in a tailor's life are:
1. The day he buys the boat,
2. The day he sells the boat, and
3. The day his best friend buys a boat.

I have now opted for number three. I am a captain for Clasic Harbor line (sail-nyc.com).
 

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