I created a little program to generate the components for a Portolan Chart for this map: [link]
I will post the program, but for now, here's an SVG output for a complete set of lines for 16 points, with a compass rose at each one, and a circumcircle. Just delete the bits you don't need.
The compasses are all clones of a template stored in the defs header. If they don't copy properly between files, try breaking the link (Details will vary with your vector editor)
If you don't have a vector editor, Inkscape is available for free. You can use it to remove the unneeded bits and render it to a raster image at whatever size you need.
Please attribute as:Portolan Chart Lines
, Copyright 2010, Kevin Michael Smith. Used under the terms of the Creative Commons Attribution License 3.0
Including that in the description on dA is sufficient.