Have you used 10-point dividers OR Incra Rulers?

I work offshore and we are constantly having to lay Lat & Long coordinates on [Bathymetric and other <font size="-1]proprietary</font> charts. Up untill today I’ve stolen a trick from my Lran C days… the ten point divider:

[img]http://ec1.images-amazon.com/images/I/51v9g42vsmL.AA280.jpg" border=“0” alt=“ten point divider” hspace=“12” vspace=“12” width=“280” height=“280” />

It works great but still has a few limitations. Today over at Kevin Kelly’s the awesome blog [URL=http://www.kk.org/cooltools/" title=“cool tools]Cool Tools I found these [URL=http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FIncra-G4888-Marking-T-Rule-18%2Fdp%2FB0000TFHLI%3Fie%3DUTF8%26s%3Dhi%26qid%3D1182083104%26sr%3D8-3&tag=gcaptaincom-20&linkCode=ur2&camp=1789&creative=9325” target="_blank]Incra Rulers:

[URL=http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FIncra-G4888-Marking-T-Rule-18%2Fdp%2FB0000TFHLI%3Fie%3DUTF8%26s%3Dhi%26qid%3D1182083104%26sr%3D8-3&tag=gcaptaincom-20&linkCode=ur2&camp=1789&creative=9325" target="_blank][img]http://www.kk.org/cooltools/archives/ruler.jpg" border=“0” hspace=“12” vspace=“12” width=“185” height=“185” /> [URL=http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FIncra-G4888-Marking-T-Rule-18%2Fdp%2FB0000TFHLI%3Fie%3DUTF8%26s%3Dhi%26qid%3D1182083104%26sr%3D8-3&tag=gcaptaincom-20&linkCode=ur2&camp=1789&creative=9325" target="_blank][img]http://www.kk.org/cooltools/archives/ruler2.jpg" border=“0” hspace=“12” vspace=“12” width=“250” />](http://en.wikipedia.org/wiki/Bathymetric_charts" title="What are Bathymetric Charts?)

They seem perfect for this task! …does anyone have experience using them?