Encountering a hurricane at sea - how big could the waves get?

[jhetfield]

Have any of you ever been caught at sea on a sailboat during a hurricane or typhoon?

Because I just found a video of a hurricane's true power in the open ocean.

HUGE SHIP - HORRIFIC HURRICANE - YouTube

How many feet tall do you think were the waves in this video?

It's hard to imagine any type of sailboat to survive something like this!

[SkiprJohn]

Never been through a hurricane any of my sailboats but have gone through two hurricanes on Navy Cruisers and one Typhoon (EASTPac hurricane) on a Navy Destroyer.

Waves were well over the bridge of the ships I was aboard and the bridges were 40 to 50 feet high. How tall were the waves? One can only guess.

You want to avoid such storms if at all possible. In the case of the hurricanes we needed to leave port because it was safer to be at sea during the fiercest and the one typhoon we were already in the Straits of Taiwan. There are plenty of videos of sailboats in extreme weather. Just search around a bit.

[CRM]

Early in my career, I worked with oceanographers measuring waves in open water in the North Sea between Scotland and Norway. We measured, not just observed, waves in excess of 100 feet trough to crest. Although, technically, they were not breaking waves, the sustained hurricane++ winds were blowing the crests off the waves so that the effect on a small boat would have been about the same as breaking waves. This is a condition that clearly must be avoided.

[Lagoon4us]

Not sure i'd like too at all, Rule 1 to....... avoid big blows!!!!

Cruising daily with the 'Meltimi' (25/45+ knots) is bad enough!

[Hud3]

Hurricane force winds in the open ocean (long fetch) typically produce waves of 60 feet or more. The most sustained wind I've experienced offshore was 40-45 knots. The waves were 25 feet or so, as reported by NOAA.

It's very hard to estimate wave heights by eye, by the way, and waves always look smaller than they actually are in still photos or video.

.

[barnakiel]

Hello again ;-)

They can get very big. See the table above then add a margin as some waves interfere and result in freak one-off events that can be 2 maybe 3 times larger. I think waves of around 100ft have been reported.

And yet: worry NOT about the extra big ones as even the smaller ones can smack your boat flat and over and render her, and you, inoperable.

Some say it takes a breaking wave of about half your boat's LOA to roll you over. For a typical 35' boat this would mean a wave of 15' or so can capsize her. And 15' waves are quite common in bad weather.

G oogle some. You will find PLENTY of relevant info, images and some cool Y outube videos.

Cheers,
b.

[Hannah on 'Rita T']

I was out there in Hurricane Mitch in '98 in a 50-foot custom Kanter and I can tell you we were much more concerned with steering down the waves than with the height of the waves. I can't remember ever looking up to the spreaders to check. We had two helms persons on board and switched every 20 minutes for about four hours. Too tired to be scared.

[jhetfield]

Originally Posted by CRM

Early in my career, I worked with oceanographers measuring waves in open water in the North Sea between Scotland and Norway. We measured, not just observed, waves in excess of 100 feet trough to crest. Although, technically, they were not breaking waves, the sustained hurricane++ winds were blowing the crests off the waves so that the effect on a small boat would have been about the same as breaking waves. This is a condition that clearly must be avoided.

They were saying during the Perfect Storm of 1991, a buoy off the coast of Nova Scotia reported a wave height of 101 feet, the highest ever recorded in the province's offshore waters.

[Vasco]

You know it's bad when a large vessel like that has to take the seas one at a time. Steering into each wave in a confused sea. Been there a few times but was much too young to really understand how perilous it was.

[ranger58sb]

Originally Posted by jhetfield

They were saying during the Perfect Storm of 1991, a buoy off the coast of Nova Scotia reported a wave height of 101 feet, the highest ever recorded in the province's offshore waters.

Woof!

Would that buoy measurement be just height variation above normal sea state... so crest to trough would have been ~202' ??

-Chris

[Vasco]

Originally Posted by ranger42c

Woof!

Would that buoy measurement be just height variation above normal sea state... so crest to trough would have been ~202' ??

-Chris

Wave height is measured crest to trough.

[ranger58sb]

Originally Posted by Vasco

Wave height is measured crest to trough.

That's what I've always thought... but I'm often surprised by folks around here who say they've just come in from 4-5' seas (!!!!) on the Chesapeake... when the nearby buoy says 1.5'


Ah. Edit: Yep, sorry meant to say .5m, sorta equivalent to a fixed site report (which are in feet around here) of 1.5'.

-Chris

[bbowers2004]

Don't bouys report meters?

[GordMay]

“... In Hurricane Katrina in August 2005 the largest waves, up to 40 feet, were found near the strongest winds.
In September 2004, scientists with the Naval Research Laboratory-Stennis Space Center, Bay St. Louis, Miss., measured a record-size ocean wave - a whopping 91 feet - when the eye wall of Hurricane Ivan passed over sensors in open water over the Gulf of Mexico ...”

➥ NASA - NASA Technology Captures Massive Hurricane Waves

[CRM]

I'm not an oceanographer, but it is my understanding that the table posted by Hud3 in Post #5 was developed for the design of fixed structures in the open ocean, so the crest elevations shown are significant wave crest elevation above mean low tide for long-crested waves (not rogue waves). These are not trough to crest heights. Therefore, the predicted heights are in line with the figures given in other posts of 90+ feet for wave trough to crest.

Large naval vessels and commercial ships may choose to go to sea in extreme storm conditions like these, but being an early arrival at a good hurricane hole is a much better choice for the rest of us.