You could also do it mathematically
(Should also be possible with nodes)
n = 500;
w = 10;
h = 4;
x = 0..Math.PI*2*10..#n;
y = Math.Sin(0..360*w..#n) * (h..0.1..#n);
p = Point.ByCoordinates(x,y);
c = NurbsCurve.ByPoints(p);
To make it flow along a base curve, a little more work
//Base Curve
c1 = NurbsCurve.ByPoints
(Point.ByCoordinates([0,10,50],[0,10,0]));
//Number of Divisions
n = 500;
//Scale Wave Extent
w = 10;
//Scale Wave Height
h = 5;
//Points on Curve
p1 = c1.PointAtParameter(0..1..#n);
//Normal at Points
n1 = c1.NormalAtParameter(0..1..#n);
//Scale wrt Base Curve Length
s = c1.Length/(Math.PiTimes2*w);
y = Math.Sin(0..360*w..#n) * (h..0.1..#n) * s;
p2 = p1.Translate(n1,y);
//Nurbs Curve
c2 = NurbsCurve.ByPoints(p2);