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ApS · 05-06-2005, 08:20 PM

With the weekend weather looking gloomy and windy, I did a quick boating survey of forty breakwaters near me at noon today. Of the 40, 10 were of the "gap" variety, allowing a space between shore and the breakwater.

Instead of a six-foot gap, however, none exceeded three feet and one "gap" had been filled in (with small rocks) by the homeowner. (Not counted, and would have been #41).

Old homes that I knew from past years were of the non-gap design, so DES has likely instituted this change to the "gap" variety in recent years.

As to there not being any sand, my own dock area has been filled by sand originating from a neighbor's driveway that was washed away in a July 6th 2000 storm -- at 4:30PM. Sand fill from new construction near me has washed over a silt fence and also entered the lake -- upwind of me, and will be here soon enough.

But there is natural sand and soil continuously moving into the lake too -- and the prevailing winds move it. Sand is created even at the peaks of New Hampshire mountains and can be seen in pockets at the summit. Millennia of lightning strikes and ice fractures is supposed to account for it.

Here's more than anyone would want to know on the movement of sand along shorelines: http://www3.csc.noaa.gov/beachnouris...o/shorelin.htm

Another consideration in your breakwater design is to allow some space under your boat for up-and-down water movement. Large, long, waves will still produce motion in the protected area. Season-end depths may end up inadequate too.

If the bottom there is a rock ledge and you want to stay with a big boat, it may be possible to dynamite the ledge, which would simultaneously provide a supply of large boulders for the breakwater. (That was done for the Walgreen's boathouse and moat, and I think everybody around Winnipesaukee knew exactly when that was done).

I'd be curious as to the rate(s) and range of your estimates.

05-06-2005, 08:20 PM	#23
ApS Senior Member Join Date: Jan 2005 Location: Florida (Sebring & Keys), Wolfeboro Posts: 5,937 Thanks: 2,205 Thanked 776 Times in 553 Posts	Dynamite idea. With the weekend weather looking gloomy and windy, I did a quick boating survey of forty breakwaters near me at noon today. Of the 40, 10 were of the "gap" variety, allowing a space between shore and the breakwater. Instead of a six-foot gap, however, none exceeded three feet and one "gap" had been filled in (with small rocks) by the homeowner. (Not counted, and would have been #41). Old homes that I knew from past years were of the non-gap design, so DES has likely instituted this change to the "gap" variety in recent years. As to there not being any sand, my own dock area has been filled by sand originating from a neighbor's driveway that was washed away in a July 6th 2000 storm -- at 4:30PM. Sand fill from new construction near me has washed over a silt fence and also entered the lake -- upwind of me, and will be here soon enough. But there is natural sand and soil continuously moving into the lake too -- and the prevailing winds move it. Sand is created even at the peaks of New Hampshire mountains and can be seen in pockets at the summit. Millennia of lightning strikes and ice fractures is supposed to account for it. Here's more than anyone would want to know on the movement of sand along shorelines: http://www3.csc.noaa.gov/beachnouris...o/shorelin.htm Another consideration in your breakwater design is to allow some space under your boat for up-and-down water movement. Large, long, waves will still produce motion in the protected area. Season-end depths may end up inadequate too. If the bottom there is a rock ledge and you want to stay with a big boat, it may be possible to dynamite the ledge, which would simultaneously provide a supply of large boulders for the breakwater. (That was done for the Walgreen's boathouse and moat, and I think everybody around Winnipesaukee knew exactly when that was done). I'd be curious as to the rate(s) and range of your estimates.