I grew up around boats, and splicing lines was one of the basic tasks to learn as a kid. A "Fid" is the tool that we used. We spliced ski, dock, and anchor lines all the time.
Not sure about spectra's small diameter, but every boater should have one nonetheless.
Here's an example of one available, but the more basic ones I've used work just fine... http://www.fid-o.com/the_fid-o_splicing_tool.htm
(Message edited by rio_sanger on January 20, 2010)