Wave Height Estimation; Differences Between Waves on Various Bodies of Water
Posted: Tue Aug 30, 2016 8:55 am
Let's tackle the differences in waves on different bodies of water first, as it's easiest:
A four-foot high wave on an inland lake or small body of water can generally only be developed under pretty harsh wind conditions--meaning very closely stacked waves with steep faces, probably--almost surely--whitecapping, and any spray developed by your boat will go soaring off in the wind. This is a nasty situation in ANY classic Boston Whaler boat, and a wet situation in almost any boat as you would be fortunate to ever split the wind perfectly. You're gonna get wet at the helm from the left or the right (or from the front) without canvas or a windshield.
A four-foot high wave on a medium body of water, like the Great Lakes, major bays like San Francisco, Chesapeake, Puget Sound, etc,. can vary from the conditions mentioned above to more like an ocean wave; it depends on conditions. These are weird bodies of water because the fetch of a steady, smooth breeze could be great enough to generate larger waves without the chaos required to generate a four-footer on an inland lake.
A four-foot high wave on the ocean is generally background swell for most of our California members. This is no problem. I have heard these members refer to waves differently: swell v. wind blown chop. It would help our Gulf, Atlantic, and Pacific coast members to remember that midwestern boaters almost never have swell and almost always are describing windblown chop when talking about waves
Wave Estimation
It is clear that there is quite a variance in describing waves. It also seems that there is a tendency to overestimate a wave's height. As an example, I took a few of my summer crew of college students around Marquette Island on Lake Huron earlier this summer. We went straight into an east wind with three to four-foot waves in a Guardian 22. They later estimated the wave height at eight to ten feet. Well, THEY were, in fact, eight to ten feet above the water a few times as we worked our way through the waves, but the wave height never exceeded an occasional six foot monster. Whenever I estimate wave height without buoy data, I tend to give my initial estimate a bit of a trim to keep myself honest.
How do you try to help yourself make an accurate estimation of wave height when you're in the Whaler?
A four-foot high wave on an inland lake or small body of water can generally only be developed under pretty harsh wind conditions--meaning very closely stacked waves with steep faces, probably--almost surely--whitecapping, and any spray developed by your boat will go soaring off in the wind. This is a nasty situation in ANY classic Boston Whaler boat, and a wet situation in almost any boat as you would be fortunate to ever split the wind perfectly. You're gonna get wet at the helm from the left or the right (or from the front) without canvas or a windshield.
A four-foot high wave on a medium body of water, like the Great Lakes, major bays like San Francisco, Chesapeake, Puget Sound, etc,. can vary from the conditions mentioned above to more like an ocean wave; it depends on conditions. These are weird bodies of water because the fetch of a steady, smooth breeze could be great enough to generate larger waves without the chaos required to generate a four-footer on an inland lake.
A four-foot high wave on the ocean is generally background swell for most of our California members. This is no problem. I have heard these members refer to waves differently: swell v. wind blown chop. It would help our Gulf, Atlantic, and Pacific coast members to remember that midwestern boaters almost never have swell and almost always are describing windblown chop when talking about waves
Wave Estimation
It is clear that there is quite a variance in describing waves. It also seems that there is a tendency to overestimate a wave's height. As an example, I took a few of my summer crew of college students around Marquette Island on Lake Huron earlier this summer. We went straight into an east wind with three to four-foot waves in a Guardian 22. They later estimated the wave height at eight to ten feet. Well, THEY were, in fact, eight to ten feet above the water a few times as we worked our way through the waves, but the wave height never exceeded an occasional six foot monster. Whenever I estimate wave height without buoy data, I tend to give my initial estimate a bit of a trim to keep myself honest.
How do you try to help yourself make an accurate estimation of wave height when you're in the Whaler?