Yes, you'll see an article at that site about checking your boat for
correct potentials and how to fix problems discovered. You don't need a
downrigger. Use an old zinc hooked to a piece of wire and dangle over the
side. Check voltage between that wire and ground.
G
"nospam please" wrote in message
...
"Gordon" wrote in message
...
Do a google search on Proline fishing black boxes. An article in there
about how to check your boat may help you.
Gordon

Are you thinking about the Pro-Troll Blackbox maybe?
http://www.protroll.com/blkboxbook.html