Wave Heights

M

MOOSE

Member
Through the marvels of the internet I was able yesterday to observe various conditions of wind and waves as a gale made its way across Lake Superior. I saw winds peak out at 44 knots and wave heights to near 15 feet. I was glad I was at home. While off-shore buoys obviously have the technology to measure wave heights accurately, it got me thinking again about how the rest of us do it.

Estimated wave heights no doubt vary with the size of one’s vessel and how frightened one is. I have had people tell me they’ve been out in ten foot waves on our large, but inland, lake. An engineer friend of mine has a program which calculates theoretical maximum wave height given the parameters of wind speed, duration, and fetch. And plugging in some very high values for each of these would indicate a potential maximum of less than five feet.

So how do most of you big-water Brats estimate wave height? Is it just a guess influenced by the pucker factor? Is it based on what you hear off the weather radio, as in “Oh, so that’s what a two-meter wave is!”? I keep looking and looking at waves and have yet to come up with a good method.

As an aside, I found a good article on wave heights at http://vos.noaa.gov/MWL/aug_05/nws.shtml It talks about the relationship between predicted wave heights and what the maximum wave height might actually be.

Al
 
I look at wave height as being from the bottom of the trough to the top of the crest. The worst water I have been in was out at Sekiu. We had 12 ft swells (according to my fish finder) with 4 ft wind waves. Now my sled at rest only has 32" sides so a 4 ft wave is really bad stuff to be in! And trust me, we were on our way in but had 5 miles to go as we had been in the middle of the Straight when the storm pushed in. Fishing was great so we put off going in until it got uncomfortable to be there (about a 2 1/2' wave on top of the swells). Going back in we were limited to about 7 or 8 mph so it was slow going.

The interesting thing about the swells is that they don't make too much difference UNTIL they get really close together. It is kind of unerving to be fishing and having the fish 10 ABOVE the boat though!
 
Just a thought; even though we have verrry mild weather in San Diego, we do have swells. The swells are created by remote storms, and early fall is mild. Plus, on top of swells, there are wind vaves and all in all, don't always count on 1-2 swells, with no wind. 3-4 ft waves (including swells,) are exciting.

However, if anyone tells you about the 10' waves in So. Cal, they've been drinking.

Added the So Cal for 10' waves. The Great Lakes is rough. Roughest trip I've been on was Lake Erie, one night

Boris
 
I posted earlier concerning a Senator in PA that wants to charge for using the NOAA weather bouys.

I use the bouys quite often for realtime reports. We already lost a very important bouy in our area that I used to view when I launched out of Port San Luis.
 
Moose: Lake Superior waves reported at 14-0 foot on Wed. Even the 900 - 1000 foot Ore-boats stayed in port .

Jack on C-Otter.
 
I,m new to boating but comming back from the Desolation Sound trip off
the SW tip of Texada Island the waves were 3-4 feet. I got the size from
the Halabiut Bank Bouy those were to big for me to cross the St. of
Georgia. I was VERY glad to go to Secret Cove and have a nice dinner.
The next morning they were ripples and we ran all the way to Anacortes
I for one was glad for those bouy reports. Was I a chicken or is 3-4 foot
more than you all like to run in????????????????????????
SIZE MATTERS TO ME
:smiled john schuler :smiled
 
John,
It's not the size that concerns me---- it's the period. I've been in 9' at 8 seconds--- now thats bloody steep! 3-4 feet at 5 seconds is a bumpy ride, while 3-4 feet at 15 seconds is nothing.
Take a small swell spaced wide apart and add some 20 knot wind waves will be bumpy.
When I look at the bouys, I like to look at all of the information. Then I'll look at the wind history, that will show what has been happening morning through the day and evening- that will give you an idea of what to expect during the day---------------BUT, the weather, she is fickle, she changes on a whim!
 
I always think the wave heights are more than forcaste by NOAA on VHF. My wife hates rough water (inner ear we think) and really gets up-set when I make a mistake. Here on the Chesapeke we try to cross in almost a dead calm condition. I have tried going out when the forcast was 1 foot or less and had waves splashing the windshield.

The boat can take a lot more than Pat can feel good about. She controls the cruising kitty so we stay in on windy days.

Fred, Pat and Mr Black
 
In the spring of 1990, I experienced a nightmare on the Strait of Juan De Fuca. No swell, 60 mph sustained winds, and 8 to 10 foot wind waves. The morning started out flat calm. Seven people were lost, several boats got swamped and the Port Angeles Coast Guard had over 50 distress calls in 30 minutes.

I didn't really know what kind of boat I had then, but now I do!

Jon
 
Worse I have been in was in 94.We were taking water 6 ft deep over the flight deck of a LSB. Thats a small carrier. but it only lasted for 18 hours. I was one of the few that did not get sick.

For fun we hung a pen from a line taped to the wall. we marked how high the end of the pen swung out to the side. At one point it was at 40degrees from center. God I hate the navy. U.S.M.C
 
Ahhh Navy days. Thanks for reminding me, Tom.

Worse for me was coming out of Holy Loch Scotland into state 5 seas (4 meter waves) in a big black 425 ft. long submarine on the surface. At one point, with 3 men on top of the sail, a rogue wave drove us down to 70 ft. depth! We popped back up with nothing more than three very cold very wet crewmembers who needed relief and a change of duds, but we were never more glad to reach the 50 fathom curve and dive down where it was peaceful.

On a second occasion as Diving Officer I was in charge of keeping the boat at periscope depth (62 ft.) in similar seas while preparing to surface. We broached (my bad), I turned to the skipper and said "32 ft. and holding, zero pressure in the boat" which is what the DO says AFTER successfully surfacing. He just laughed and made me get it back to 62 ft. :roll: It took over 20,000 lbs of sea water in trim tanks and almost 10 minutes to get that big beast below again, only to hear "Surface the boat." ARGHHHHHH

The best Marine is a Submarine.

Don
 
Don-

Doesn't sound like C-Dory weather to me!!!

Are you coming to the CBC&SBS? You and Charlie could compare Navy stories and keep us entertained! Would be fun to meet both of you along with all the new members attending. Really looking forward to it. Joe.
 
Joe, you can't imagine how much I'm looking forward to getting up there. I hear it's a good way to get a C-Dory cap too, because my dealer kind'a forgot to include one in the purchase.

Unfortunately, the best way to make God laugh is to make plans. I came within a whisker of getting to Sequim and even had airline tickets on hold, but a last minute Elder Care crisis cancelled it all. Being a sole surviving child can be pretty limiting but it's something most everyone goes through eventually. I figure it's Karmic payback for High School antics that caused her so much grief.

I think both Dusty and Charlie have a much larger bucket of sea state tales to draw from than I do, and I'm looking forward to meeting them too. Dusty's been both above and below the water and Charlie rode "Targets" most of his career, including some (urp) Frigates, so I'm sure he's got some "State five" tales to tell. After all, on Nuke boats we simply dove below the wave action to drink our coffee undisturbed.

Actually, I have a suspicion that Dusty could tell some great "Wave" tales too, seeing as how he was the Dashing Aviator those Wave Nurses just loved to meet....


Don
 
Fish Tails (tales?!) is right on. It is the distance between the crests. Three hours of steady five footers was a tough crossing (Strait of Georgia last April) but the boat handled it well. I turned it around last winter with eight footers ahead. We left the boat in the San Juans and took the Parakleet (area water taxi) across. Rescued some fool kayakers in the middle of Rosario that day. They were not having fun.

We do not have swell in the Puget Sound - except in the Straight of Juan de Fuca at times. Waves can tend to get close together. When the windshield is green, you should have already turned around! Actually, speed of the boat is an important factor to. I was 9 to 10 kts in my crossing of St. of Georgia and rolled right over all - er, most of the waves!
 
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