'Lo All, All the discussion of wakes reminds me of what happened here in our little bayou, about a mile off of the Gulf Intracoastal WaterWay (GIWW). We bought this property shortly before I retired from the USAF. Then I had to go to New Jersey for about 8.5 years to make some money so we could build a house here. While we were gone, we lost about 10' of land due to "erosion" on the northeast end of our lot. Of course, the State says once it is gone, it is gone and you cannot recover it. I was working for General Electric on the Aegis program, so had access to some very talented folks. I asked one multi-disciplined engineer about the loss of land. He asked some very specific questions. Among them was the shape of the bayou (fairly long and narrow, about 12' deep), type of bottom (sand) and the amount of vegetation at the place I lost the ground (none). He asked me to do two things: measure the angle of the sand at the water's edge and to see if there was any obvious reason that there was no vegetation near shore. The first was easy to answer: about 13 degrees. This was the "angle of repose". The vegetation question's answer was less obvious. Sea grass grew up to about 10-12' feet from shore, but no closer in that area, which was about 50' long. Sea grass and reeds grew on both sides of this area, up to and on shore. However, on one trip down from NJ, it had been raining heavily and, when watching the bottom, there were numerous vents where fresh water was boiling up. The answer then became obvious: natural artesian fresh water was preventing the growth of seagrass. (This is quite normal in this area.) My friend, a hydro-geological engineer (or something like that), then said that what was happening was that mother nature's waves traveled along the shore for the length of the bayou and never caused problems because their energy was expended parallel to the shore. Then boats came along and made wakes that traveled somewhere near perpendicular to the shore. They were the problem. What he said happens, is that the wave carries sand with it up the bank, and deposits sand up to the angle of repose, any sand that would increase this natural angle (which is determined by the type and size of the grains of sand - think of stacks of oranges in the store) are carried back down the bank and into the natural bed of water, creating shoals. This explains why sand barrier islands are built up over years, and torn asunder during a hurricane. However, in my case, there were no sea grasses to stop the waves from traveling up the bank, therefore, they would go up as far as the wave energy made it go, which was several feet for even a small wave. Larger perpendicular waves traveled much farther as they have a much larger energy component. As the wave travels up the bank, any sand or other matter that is above a line created by the angle of repose is washed back into the body of water. This means that the bank is undermined, eventually, trees, bushes, etc., end up with their roots in the salt water and are killed. The bank slowly caves in. Over time, there is a loss of land, trees and bushes. When we moved back down here, we had lost about 10' of land where there was no grass/reeds to impede the waves. As soon as I could, I built a sea wall. When I was building it, I could stick a shovel handle up under the root mass as far as I could reach. (Arm and shovel handle were about 10' long.) After building the sea wall, I poked holes down between the oak tree roots so that I could fill the voids as best as I could. Still, the ground has settled a lot over the years and several beautifully unique oak trees have slowly tipped over. When they hit the deck, they will, hopefully, stop tipping -- about 18" to go. My grandkids call them the "sitting" trees, because they like to sit on the large trunk/branches that are horizontal, and just above the deck. My point: boat wakes do not just rock boats! Some shorelines are very prone to extreme erosion from large boat wakes, but have been impervious to nature's waves because of the relatively smaller size and the direction of those waves. When you are in a narrow channel, look at the shoreline and see if the waves can flow up under the bank. If they can, you may be destroying the shoreline if your wake runs up to the top of the bank created by the "angle of repose", even if it is obscured by the overhanging root mass. No damage is done if the wave doesn't reach the top, where the sand has not been eroded, but if the wave extends to the top, it will carry away the sand/soil that creates the bank and holds the trees. The cumulative effect is easy to see - trees tipping over that are several feet up the bank. The Eastern sea shore's ICW has shown the effect of this for years. The Corps of Engineers says the design depth is 12' for most of the ICW. Much of it is far less, as what was on the shore, is now on the bottom. Not all of the filling in of the channel can be attributed to boat wakes, of course, but much is, in MHO. Try to take care of our playgrounds! OK, I'm off my soapbox. Take care and be safe! Wayne M/V Celestial Albin 43 Sundeck