David, Just a quick note, Navman instruments are now marketed in the US under the Northstar name. Same stuff. I am using the 3100 series depth and knotmeter. Wonderful gear, they work fabulous and easy to read. Think spring! -4 in Mn this morning.... Bones ____________________________________________________________ New to Digital Photography? Click Here. http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTDvmPnujTMfBkmfV7lv0qqNu0W...