Wave height question?

[PDnaz]

I have found it depends on the size of your boat in terms of wave height.
smaller boat waves seem bigger,

[B can man]

Weather buoy 45005 is the most accurate way I have found to tell current wave conditions (when DOUBLED). From my experience this season so far, that is verrrry accurate. Thanks for sharing that with me earlier this year guys.

The rule of 1ft for every 5mph of wind is accurate enough as a starting point, but is very dependent on the wind direction and where you plan to fish. 12mph wind out of the east or northeast can churn up 3-4ft'ers when not knocked down by an island or peninsula. 12mph winds out of the south seem to usually only kick up 1-2ft'ers.

[Eyecutioner]

2 feet or less could be glass calm, considering the "less" report. I have been anchored perching with the wind blowing from the east, flags on Kelly's Island blowing south, and flags dead calm when I get back to the dock. Open water measurements are always different that near shore ( five miles or less).

Buoys measure the height from a calm lake to the top of a wave. They do not measure the trough, hence double the number to get an idea of how much rock "n" roll is expected. For example, 2-4 foot waves will have a trough of about the same height so you will have a 4-8 foot distance from top of wave to bottom of trough.

Thanks for that explanation. At least I now know why to double the number. No wonder those 2 footers seemed so high.

[TIN CAN]

The buoy does not actually measure the height of the wave, instead an onboard 3 axis accelerometer measures the speed of rise and fall and the duration in seconds and an then computes a theoretical distance in feet or meters that represents wave height. They are fairly accurate estimates of wave height from top to bottom. The best indicator they provide is contained in the "dominate wave duration column. waves of over 4 and 5 second duration are big.

Another factor to consider in wind wave calculations aside from "Fetch" or the distance the wind affects the water is air temperature. A 15 knot NE wind on an 85 degree day will provide minimal water displacement however the same wind on a 40 degree day will provide significant waves.

[PatSea]

TIN CAN, your comment about the affect of air temperature on wave height is very interesting, and one that I have experienced over the years, but care to explain further? Does it have to do with the density af the air exerting more force on the water surface, thuis causing larger wave heights?

[TIN CAN]

As wind is actually a thinner version of liquid, remember gas to liquid to solid with temp fall. The colder that mass becomes the more dense it becomes. For this reason a jet flying at low altitude with denser air will burn significantly more fuel than at 30,000 feet with less drag from air density.

It's also the reason those poor guys on deadliest catch are nearly always in the soup, it's because of the very cold climate they operate in. If you consider that most days non fishable on lake Erie are the result of a passing cold front with a low pressure system. High temps and high pressure result in sunny flat breathless days on the lake. Cold, low pressure will get you wet from blow back as you bump along.

And yes that's the reason for the affect.

[pap]

As wind is actually a thinner version of liquid, remember gas to liquid to solid with temp fall. The colder that mass becomes the more dense it becomes. For this reason a jet flying at low altitude with denser air will burn significantly more fuel than at 30,000 feet with less drag from air density.

It's also the reason those poor guys on deadliest catch are nearly always in the soup, it's because of the very cold climate they operate in. If you consider that most days non fishable on lake Erie are the result of a passing cold front with a low pressure system. High temps and high pressure result in sunny flat breathless days on the lake. Cold, low pressure will get you wet from blow back as you bump along.

And yes that's the reason for the affect.

Very well said Tin Can, That is why in the early season 10-12mph winds the lake is unfishable and in the summer on a nice day those # you wouldn't think twice about going out

[bowguy84]

I guess I just don't understand how this works. Why does the buoy only measure up?

I don't know the answer to that . Thays just what I've been told by a lot of captains around my marina maybe tincan can tell u why

[bowguy84]

Actually I just read post 12 on the new weather buoy it takes a average of the trough to the top of the biggest 1/3 of the waves so people usually double that because there are likley waves that big out there becaused of the average thing.

[limitlypps]

I ran 22 miles east from Colchester to Pt Pelee, the winds were west around 10 knots with a two ft chop and running to Pelee was a breeze until I was about 4 miles from destination near the shipping channel, that 2ft chop gradually turned into 3-4's, it was noted that the winds at the Sandusky buoy were west at 16 knots.As the morning progressed those 3's and 4's turned into 6- and 7's, that absolutely sucked as we tried in vain to bring in hogs and lost them in the troughs.By noon the body and boat were in fatigue mode and we lost as many fish we caught, 28, 8 short of limit, but I said one more pass in this chit ain't gonna happen.A 40 minute run there took two hrs. to get back and low and behold there was still a mere 2ft chop as we headed back east 4 miles from home.So I guess the moral to the story is, always expect the unexpected when you travel out to sea and wave heights do change and vary with wind direction, speed and water depths.
Boy is my body ever sore today.......